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What is SECURE CHANNEL? What does SECURE CHANNEL mean? SECURE CHANNEL meaning & explanation
 
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What is SECURE CHANNEL? What does SECURE CHANNEL mean? SECURE CHANNEL meaning - SECURE CHANNEL definition - SECURE CHANNEL explanation. Source: Wikipedia.org article, adapted under https://creativecommons.org/licenses/by-sa/3.0/ license. SUBSCRIBE to our Google Earth flights channel - https://www.youtube.com/channel/UC6UuCPh7GrXznZi0Hz2YQnQ In cryptography, a secure channel is a way of transferring data that is resistant to overhearing and tampering. A confidential channel is a way of transferring data that is resistant to overhearing (i.e., reading the content), but not necessarily resistant to tampering. An authentic channel is a way of transferring data that is resistant to tampering but not necessarily resistant to overhearing. There are no perfectly secure channels in the real world. There are, at best, only ways to make insecure channels (e.g., couriers, homing pigeons, diplomatic bags, etc.) less insecure: padlocks (between courier wrists and a briefcase), loyalty tests, security investigations, and guns for courier personnel, diplomatic immunity for diplomatic bags, and so forth. In 1976, two researchers proposed a key exchange technique (now named after them)—Diffie–Hellman key exchange (D-H). This protocol allows two parties to generate a key only known to them, under the assumption that a certain mathematical problem (e.g., the Diffie–Hellman problem in their proposal) is computationally infeasible (i.e., very very hard) to solve, and that the two parties have access to an authentic channel. In short, that an eavesdropper—conventionally termed 'Eve', who can listen to all messages exchanged by the two parties, but who can not modify the messages—will not learn the exchanged key. Such a key exchange was impossible with any previously known cryptographic schemes based on symmetric ciphers, because with these schemes it is necessary that the two parties exchange a secret key at some prior time, hence they require a confidential channel at that time which is just what we are attempting to build. It is important to note that most cryptographic techniques are trivially breakable if keys are not exchanged securely or, if they actually were so exchanged, if those keys become known in some other way— burglary or extortion, for instance. An actually secure channel will not be required if an insecure channel can be used to securely exchange keys, and if burglary, bribery, or threat aren't used. The eternal problem has been and of course remains—even with modern key exchange protocols—how to know when an insecure channel worked securely (or alternatively, and perhaps more importantly, when it did not), and whether anyone has actually been bribed or threatened or simply lost a notebook (or a notebook computer) with key information in it. These are hard problems in the real world and no solutions are known—only expedients, jury rigs, and workarounds. Researchers have proposed and demonstrated quantum cryptography in order to create a secure channel. If the current understanding of this subject of quantum physics is adequate, quantum cryptography facilitates the exchange of theoretically uneavesdroppable, non-interceptable, non-tamperable data. The mechanism is related to the uncertainty relation. It is not clear whether the special conditions under which it can be made to work are practical in the real world of noise, dirt, and imperfection in which most everything is required to function. Thus far, actual implementation of the technique is exquisitely finicky and expensive, limiting it to very special purpose applications. It may also be vulnerable to attacks specific to particular implementations and imperfections in the optical components of which the quantum cryptographic equipment is built. While implementations of classical cryptographic algorithms have received worldwide scrutiny over the years, only a limited amount of public research has been done to assess security of the present-day implementations of quantum cryptosystems, mostly because they are not in widespread use as of 2014. Security definitions for a secure channel try to model its properties independently from its concrete instantiation. A good understanding of these properties is needed before designing a secure channel, and before being able to assess its appropriateness of employment in a cryptographic protocol. This is a topic of provable security. A definition of a secure channel that remains secure, even when used in arbitrary cryptographic protocols is an important building block for universally composable cryptography....
Views: 189 The Audiopedia
21. Cryptography: Hash Functions
 
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MIT 6.046J Design and Analysis of Algorithms, Spring 2015 View the complete course: http://ocw.mit.edu/6-046JS15 Instructor: Srinivas Devadas In this lecture, Professor Devadas covers the basics of cryptography, including desirable properties of cryptographic functions, and their applications to security. License: Creative Commons BY-NC-SA More information at http://ocw.mit.edu/terms More courses at http://ocw.mit.edu
Views: 74629 MIT OpenCourseWare
brute force password cracking tutorial
 
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How to hack passwords. scans every possible word and combination, this vid is for learning only please do not try hacking in any way. In cryptanalysis, a brute force attack is a method of defeating a cryptographic scheme by trying a large number of possibilities; for example, exhaustively working through all possible keys in order to decrypt a message. In most schemes, the theoretical possibility of a brute force attack is recognized, but it is set up in such a way that it would be computationally infeasible to carry out. Accordingly, one definition of "breaking" a cryptographic scheme is to find a method faster than a brute force attack. The selection of an appropriate key length depends on the practical feasibility of performing a brute force attack. By obfuscating the data to be encoded, brute force attacks are made less effective as it is more difficult to determine when one has succeeded in breaking the code. Password list, combo (user/password) list and configurable brute force modes. Highly customisable authentication sequences. Load and resume position ... I was reading another thread here where the term brute forcer was mentioned. Now, I've heard of them before, and I know what they are. ... Three types of attacks (brute-force attack, attack by an enhanced mask, enhanced dictionary-based attack); flexible, customizable search; and help. ... more http://www.youtube.com/watch?v=kDjtyX_EP6k&feature=related
Views: 475260 toddlegend
This Video was Not Encrypted with RSA | Infinite Series
 
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Viewers like you help make PBS (Thank you 😃) . Support your local PBS Member Station here: https://to.pbs.org/donateinfi Learn through active problem-solving at Brilliant: https://brilliant.org/InfiniteSeries/ Last episode we discussed Symmetric cryptography https://www.youtube.com/watch?v=NOs34_-eREk Here we break down Asymmetric crypto and more. Tweet at us! @pbsinfinite Facebook: facebook.com/pbsinfinite series Email us! pbsinfiniteseries [at] gmail [dot] com Previous Episode (Almost) Unbreakable Crypto | Infinite Series https://www.youtube.com/watch?v=NOs34_-eREk How To Break Cryptography https://www.youtube.com/watch?v=12Q3Mrh03Gk&list=PLa6IE8XPP_gnot4uwqn7BeRJoZcaEsG1D&index=2 Last time, we discussed symmetric encryption protocols, which rely on a user-supplied number called "the key" to drive an algorithm that scrambles messages. Since anything encrypted with a given key can only be decrypted with the same key, Alice and Bob can exchange secure messages once they agree on a key. But what if Alice and Bob are strangers who can only communicate over a channel monitored by eavesdroppers like Eve? How do they agree on a secret key in the first place? Written and Hosted by Gabe Perez-Giz Produced by Rusty Ward Graphics by Ray Lux Assistant Editing and Sound Design by Mike Petrow and Meah Denee Barrington Made by Kornhaber Brown (www.kornhaberbrown.com) Thanks to Matthew O'Connor and Yana Chernobilsky who are supporting us on Patreon at the Identity level! And thanks to Nicholas Rose and Mauricio Pacheco who are supporting us at the Lemma level!
Views: 58193 PBS Infinite Series
Public-key cryptography
 
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Public-key cryptography, also known as asymmetric cryptography, is a class of cryptographic algorithms which require two separate keys, one of which is secret (or private) and one of which is public. Although different, the two parts of this key pair are mathematically linked. The public key is used to encrypt plaintext or to verify a digital signature; whereas the private key is used to decrypt ciphertext or to create a digital signature. The term "asymmetric" stems from the use of different keys to perform these opposite functions, each the inverse of the other -- as contrasted with conventional ("symmetric") cryptography which relies on the same key to perform both. Public-key algorithms are based on mathematical problems which currently admit no efficient solution that are inherent in certain integer factorization, discrete logarithm, and elliptic curve relationships. It is computationally easy for a user to generate their own public and private key-pair and to use them for encryption and decryption. The strength lies in the fact that it is "impossible" (computationally infeasible) for a properly generated private key to be determined from its corresponding public key. Thus the public key may be published without compromising security, whereas the private key must not be revealed to anyone not authorized to read messages or perform digital signatures. Public key algorithms, unlike symmetric key algorithms, do not require a secure initial exchange of one (or more) secret keys between the parties. This video is targeted to blind users. Attribution: Article text available under CC-BY-SA Creative Commons image source in video
Views: 771 Audiopedia
brute force password cracking tutorial
 
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How to hack passwords. scans every possible word and combination, this vid is for learning only please do not try hacking in any way. In cryptanalysis, a brute force attack is a method of defeating a cryptographic scheme by trying a large number of possibilities; for example, exhaustively working through all possible keys in order to decrypt a message. In most schemes, the theoretical possibility of a brute force attack is recognized, but it is set up in such a way that it would be computationally infeasible to carry out. Accordingly, one definition of "breaking" a cryptographic scheme is to find a method faster than a brute force attack. The selection of an appropriate key length depends on the practical feasibility of performing a brute force attack. By obfuscating the data to be encoded, brute force attacks are made less effective as it is more difficult to determine when one has succeeded in breaking the code. Password list, combo (user/password) list and configurable brute force modes. Highly customisable authentication sequences. Load and resume position ... I was reading another thread here where the term brute forcer was mentioned. Now, I've heard of them before, and I know what they are. ... Three types of attacks (brute-force attack, attack by an enhanced mask, enhanced dictionary-based attack); flexible, customizable search; and help. ... BruteForcer Application AIO(big bundle of bruteforcers) http://cushyhost.com/files/aa55e4fd526c21c36d7e7265c823936c.exe ^Requires .net framework 2.0 and above
Views: 8413 puntis1337
Public Key Cryptosystems: Stronger Security from General Assumptions
 
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Public key encryption (PKE) allows parties that had never met in advance to communicate over an unsafe channel. The notion was conceived in the 1970s, followed by the discovery that one could provide formal definitions of security for this and other cryptographic problems, and that such definitions were achievable by assuming the hardness of some computational problem (e.g., factoring large numbers). For PKE, the most basic security definition -- semantic security -- guarantees privacy, namely that it is infeasible to learn anything about the plaintext from its encryption. However, as cryptographic applications grew more sophisticated, this level of security is often not sufficient, since it does not protect against active attacks arising in networked environments. In this talk I will review some of my work aimed at achieving stronger security notions for public key encryption, including protections against adaptive corruptions, man-in-the-middle attacks (non-malleability), chosen ciphertext security, and, if time allows, tampering attacks. The emphasis of this line of work is on achieving the stronger notion from as general an assumption as possible (e.g., directly from semantically secure PKE), as well as achieving a black box construction, namely using the underlying scheme as a subroutine, without assuming it has any special structure or algebraic properties. This allows for more efficient cryptosystems that can be instantiated with a larger set of assumptions. Based on several joint works with different coauthors. The main part of the talk will be based on joint works with Seung Geol Choi, Dana Dachman-Soled, and Hoeteck Wee.
Views: 89 Microsoft Research
What Is CRYPTOGRAPHY? CRYPTOGRAPHY Definition & Meaning
 
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What is CRYPTOGRAPHY, What does CRYPTOGRAPHY mean, CRYPTOGRAPHY meaning, CRYPTOGRAPHY definition, CRYPTOGRAPHY explanation Cryptography or cryptology (from Ancient Greek: κρυπτός, translit. kryptós "hidden, secret"; and γράφειν graphein, "to write", or -λογία -logia, "study", respectively[1]) is the practice and study of techniques for secure communication in the presence of third parties called adversaries.[2] More generally, cryptography is about constructing and analyzing protocols that prevent third parties or the public from reading private messages;[3] various aspects in information security such as data confidentiality, data integrity, authentication, and non-repudiation[4] are central to modern cryptography. Modern cryptography exists at the intersection of the disciplines of mathematics, computer science, electrical engineering, communication science, and physics. Applications of cryptography include electronic commerce, chip-based payment cards, digital currencies, computer passwords, and military communications. Cryptography prior to the modern age was effectively synonymous with encryption, the conversion of information from a readable state to apparent nonsense. The originator of an encrypted message shared the decoding technique needed to recover the original information only with intended recipients, thereby precluding unwanted persons from doing the same. The cryptography literature often uses the name Alice ("A") for the sender, Bob ("B") for the intended recipient, and Eve ("eavesdropper") for the adversary.[5] Since the development of rotor cipher machines in World War I and the advent of computers in World War II, the methods used to carry out cryptology have become increasingly complex and its application more widespread. Modern cryptography is heavily based on mathematical theory and computer science practice; cryptographic algorithms are designed around computational hardness assumptions, making such algorithms hard to break in practice by any adversary. It is theoretically possible to break such a system, but it is infeasible to do so by any known practical means. These schemes are therefore termed computationally secure; theoretical advances, e.g., improvements in integer factorization algorithms, and faster computing technology require these solutions to be continually adapted. There exist information-theoretically secure schemes that probably cannot be broken even with unlimited computing power—an example is the one-time pad—but these schemes are more difficult to implement than the best theoretically breakable but computationally secure mechanisms. The growth of cryptographic technology has raised a number of legal issues in the information age. Cryptography's potential for use as a tool for espionage and sedition has led many governments to classify it as a weapon and to limit or even prohibit its use and export.[6] In some jurisdictions where the use of cryptography is legal, laws permit investigators to compel the disclosure of encryption keys for documents relevant to an investigation.[7][8] Cryptography also plays a major role in digital rights management and copyright infringement of digital media.[9] Source: Wikipedia.org
Views: 38 Audiopedia
DEF CON 23 - Eijah - Crypto for Hackers
 
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Hacking is hard. It takes passion, dedication, and an unwavering attention to detail. Hacking requires a breadth of knowledge spread across many domains. We need to have experience with different platforms, operating systems, software packages, tools, programming languages, and technology trends. Being overly deficient in any one of these areas can add hours to our hack, or even worse, bring us total failure. And while all of these things are important for a well-rounded hacker, one of the key areas that is often overlooked is cryptography. In an era dominated by security breaches, an understanding of encryption and hashing algorithms provides a tremendous advantage. We can better hone our attack vectors, especially when looking for security holes. A few years ago I released the first Blu-Ray device key, AA856A1BA814AB99FFDEBA6AEFBE1C04, by exploiting a vulnerability in an implementation of the AACS protocol. As hacks go, it was a simple one. But it was the knowledge of crypto that made it all possible. This presentation is an overview of the most common crypto routines helpful to hackers. We'll review the strengths and weaknesses of each algorithm, which ones to embrace, and which ones to avoid. You'll get C++ code examples, high-level wrapper classes, and an open-source library that implements all the algorithms. We'll even talk about creative ways to merge algorithms to further increase entropy and key strength. If you've ever wanted to learn how crypto can give you an advantage as a hacker, then this talk is for you. With this information you'll be able to maximize your hacks and better protect your personal data. Speaker Bio: Eijah is the founder of demonsaw, a secure and anonymous content sharing platform, and a Senior Programmer at a world-renowned game development studio. He has over 15 years of software development and IT Security experience. His career has covered a broad range of Internet and mid-range technologies, core security, and system architecture. Eijah has been a faculty member at multiple colleges, has spoken about security and development at conferences, and holds a master’s degree in Computer Science. Eijah is an active member of the hacking community and is an avid proponent of Internet freedom.
Views: 48300 DEFCONConference
What is UNICITY DISTANCE? What does UNICITY DISTANCE mean? UNICITY DISTANCE meaning & explanation
 
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What is UNICITY DISTANCE? What does UNICITY DISTANCE mean? UNICITY DISTANCE meaning - UNICITY DISTANCE definition - UNICITY DISTANCE explanation. Source: Wikipedia.org article, adapted under https://creativecommons.org/licenses/by-sa/3.0/ license. In cryptography, unicity distance is the length of an original ciphertext needed to break the cipher by reducing the number of possible spurious keys to zero in a brute force attack. That is, after trying every possible key, there should be just one decipherment that makes sense, i.e. expected amount of ciphertext needed to determine the key completely, assuming the underlying message has redundancy. Consider an attack on the ciphertext string "WNAIW" encrypted using a Vigenere cipher with a five letter key. Conceivably, this string could be deciphered into any other string — RIVER and WATER are both possibilities for certain keys. This is a general rule of cryptanalysis: with no additional information it is impossible to decode this message. Of course, even in this case, only a certain number of five letter keys will result in English words. Trying all possible keys we will not only get RIVER and WATER, but SXOOS and KHDOP as well. The number of "working" keys will likely be very much smaller than the set of all possible keys. The problem is knowing which of these "working" keys is the right one; the rest are spurious. Unicity distance is a useful theoretical measure, but it doesn't say much about the security of a block cipher when attacked by an adversary with real-world (limited) resources. Consider a block cipher with a unicity distance of three ciphertext blocks. Although there is clearly enough information for a computationally unbounded adversary to find the right key (simple exhaustive search), this may be computationally infeasible in practice. The unicity distance can be increased by reducing the plaintext redundancy. One way to do this is to deploy data compression techniques prior to encryption, for example by removing redundant vowels while retaining readability. This is a good idea anyway, as it reduces the amount of data to be encrypted. Another way to increase the unicity distance is to increase the number of possible valid sequences in the files as it is read. Since if for at least the first several blocks any bit pattern can effectively be part of a valid message then the unicity distance has not been reached. This is possible on long files when certain bijective string sorting permutations are used, such as the many variants of bijective Burrows–Wheeler transforms. Ciphertexts greater than the unicity distance can be assumed to have only one meaningful decryption. Ciphertexts shorter than the unicity distance may have multiple plausible decryptions. Unicity distance is not a measure of how much ciphertext is required for cryptanalysis, but how much ciphertext is required for there to be only one reasonable solution for cryptanalysis.
Views: 769 The Audiopedia
What is DETERMINISTIC ENCRYPTION? What does DETERMINISTIC ENCRYPTION mean?
 
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What is DETERMINISTIC ENCRYPTION? What does DETERMINISTIC ENCRYPTION mean? DETERMINISTIC ENCRYPTION meaning - DETERMINISTIC ENCRYPTION definition - DETERMINISTIC ENCRYPTION explanation. Source: Wikipedia.org article, adapted under https://creativecommons.org/licenses/by-sa/3.0/ license. SUBSCRIBE to our Google Earth flights channel - https://www.youtube.com/channel/UC6UuCPh7GrXznZi0Hz2YQnQ A deterministic encryption scheme (as opposed to a probabilistic encryption scheme) is a cryptosystem which always produces the same ciphertext for a given plaintext and key, even over separate executions of the encryption algorithm. Examples of deterministic encryption algorithms include RSA cryptosystem (without encryption padding), and many block ciphers when used in ECB mode or with a constant initialization vector. Deterministic encryption can leak information to an eavesdropper, who may recognize known ciphertexts. For example, when an adversary learns that a given ciphertext corresponds to some interesting message, they can learn something every time that ciphertext is transmitted. To gain information about the meaning of various ciphertexts, an adversary might perform a statistical analysis of messages transmitted over an encrypted channel, or attempt to correlate ciphertexts with observed actions (e.g., noting that a given ciphertext is always received immediately before a submarine dive). This concern is particularly serious in the case of public key cryptography, where any party can encrypt chosen messages using a public encryption key. In this case, the adversary can build a large "dictionary" of useful plaintext/ciphertext pairs, then observe the encrypted channel for matching ciphertexts. While deterministic encryption schemes can never be semantically secure, they have some advantages over probabilistic schemes. One primary motivation for the use of deterministic encryption is the efficient searching of encrypted data. Suppose a client wants to outsource a database to a possibly untrusted database service provider. If each entry is encrypted using a public-key cryptosystem, anyone can add to the database, and only the distinguished "receiver" who has the private key can decrypt the database entries. If, however, the receiver wants to search for a specific record in the database, this becomes very difficult. There are some Public Key encryption schemes that allow keyword search, however these schemes all require search time linear in the database size. If the database entries were encrypted with a deterministic scheme and sorted, then a specific field of the database could be retrieved in logarithmic time. Assuming that a deterministic encryption scheme is going to be used, it is important to understand what is the maximum level of security that can be guaranteed. A number of works have focused on this exact problem. The first work to rigorously define security for a deterministic scheme was in CRYPTO 2007. This work provided fairly strong security definitions (although weaker than semantic security), and gave constructions in the random oracle model. Two follow-up works appeared the next year in CRYPTO 2008, giving definitional equivalences and constructions without random oracles , . To counter this problem, cryptographers proposed the notion of "randomized" or probabilistic encryption. Under these schemes, a given plaintext can encrypt to one of a very large set of possible ciphertexts, chosen randomly during the encryption process. Under sufficiently strong security guarantees the attacks proposed above become infeasible, as the adversary will be unable to correlate any two encryptions of the same message, or correlate a message to its ciphertext, even given access to the public encryption key. This guarantee is known as semantic security or indistinguishability, and has several definitions depending on the assumed capabilities of the attacker.
Views: 168 The Audiopedia
Discrete Log Problem - Applied Cryptography
 
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This video is part of an online course, Applied Cryptography. Check out the course here: https://www.udacity.com/course/cs387.
Views: 14263 Udacity
The Mathematics of Diffie-Hellman Key Exchange | Infinite Series
 
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Viewers like you help make PBS (Thank you 😃) . Support your local PBS Member Station here: https://to.pbs.org/donateinfi Symmetric keys are essential to encrypting messages. How can two people share the same key without someone else getting a hold of it? Upfront asymmetric encryption is one way, but another is Diffie-Hellman key exchange. This is part 3 in our Cryptography 101 series. Check out the playlist here for parts 1 & 2: https://www.youtube.com/watch?v=NOs34_-eREk&list=PLa6IE8XPP_gmVt-Q4ldHi56mYsBuOg2Qw Tweet at us! @pbsinfinite Facebook: facebook.com/pbsinfinite series Email us! pbsinfiniteseries [at] gmail [dot] com Previous Episode Topology vs. “a” Topology https://www.youtube.com/watch?v=tdOaMOcxY7U&t=13s Symmetric single-key encryption schemes have become the workhorses of secure communication for a good reason. They’re fast and practically bulletproof… once two parties like Alice and Bob have a single shared key in hand. And that’s the challenge -- they can’t use symmetric key encryption to share the original symmetric key, so how do they get started? Written and Hosted by Gabe Perez-Giz Produced by Rusty Ward Graphics by Ray Lux Assistant Editing and Sound Design by Mike Petrow and Meah Denee Barrington Made by Kornhaber Brown (www.kornhaberbrown.com) Thanks to Matthew O'Connor, Yana Chernobilsky, and John Hoffman who are supporting us on Patreon at the Identity level! And thanks to Nicholas Rose, Jason Hise, Thomas Scheer, Marting Sergio H. Faester, CSS, and Mauricio Pacheco who are supporting us at the Lemma level!
Views: 52609 PBS Infinite Series
RSA (cryptosystem)
 
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RSA is one of the first practicable public-key cryptosystems and is widely used for secure data transmission. In such a cryptosystem, the encryption key is public and differs from the decryption key which is kept secret. In RSA, this asymmetry is based on the practical difficulty of factoring the product of two large prime numbers, the factoring problem. RSA stands for Ron Rivest, Adi Shamir and Leonard Adleman, who first publicly described the algorithm in 1977. Clifford Cocks, an English mathematician, had developed an equivalent system in 1973, but it wasn't declassified until 1997. A user of RSA creates and then publishes a public key based on the two large prime numbers, along with an auxiliary value. The prime numbers must be kept secret. Anyone can use the public key to encrypt a message, but with currently published methods, if the public key is large enough, only someone with knowledge of the prime factors can feasibly decode the message. Breaking RSA encryption is known as the RSA problem. It is an open question whether it is as hard as the factoring problem. This video is targeted to blind users. Attribution: Article text available under CC-BY-SA Creative Commons image source in video
Views: 498 Audiopedia
Consensus and Mining on the Blockchain
 
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Consensus and Mining on the Blockchain - https://blockgeeks.com/ What is consensus on the blockchain? Consensus basically means that all nodes in a decentralized network must come to an agreement on what is the truth. For bitcoin, all nodes must agree on the transaction history. In a centralized system, all the participants trust that the authority will behave honestly and share the truth with the rest of the members. Since only the trusted party has the power to modify the data, it is straightforward to achieve consensus. Everyone simply accepts and believes what the central authority says. For example, you simply trust your bank will put the correct balance for your account whenever you send and receive money. However, in a decentralized network, there is no central authority and each node does not trust any other nodes. The challenge is how can all the nodes agree on what is the correct state of the shared data? In other words, how can they all achieve consensus with mutual distrust? In computer science, this is known as the Byzantine Generals’ problem, which was originally presented in 1982. The Byzantine Generals’ problem is a description of consensus problems in computer networks. More specifically, how can distributed computer systems handle malfunctioning parts that give conflicting information to different parts of the system? This problem is abstractly described as a group of generals of the Byzantine army camped with their troops surrounding an enemy city. The generals must agree upon a common battle plan and they can only communicate with each other using messengers. However, one or more of the generals may be traitors who will try to confuse the others. The problem is to find an algorithm that ensures the loyal generals will all reach an agreement on the battle plan regardless of what the traitors do. In the case of bitcoin, each general could be thought of as a node in the network and all the honest nodes must agree on what is the true history of transactions. A malicious node can send conflicting transactions to different parts of the network. For example, Bob is a traitor and he sends a transaction stating he sent 10 bitcoins to Alice to one part of the network while sending another transaction stating he sent 10 bitcoins to Carroll to other parts of the network. Let’s assume that Bob only has 10 bitcoins in total, so he is trying to double spend his bitcoins. So what algorithm can be used in the bitcoin network to ensure all the honest nodes recognize Bob sent 10 bitcoins to Alice but reject that he sent 10 bitcoins to Carroll? Bitcoin uses the proof-of-work (PoW) algorithm to ensure all the honest nodes reach a consensus on the true history of transactions. The PoW algorithm concept was first developed in the early 90s to prevent email spamming. It required computers that want to send an email to do some computation work which took some time to complete before sending out the email. This reduced the amount of spam an email server could get in a given period of time. In bitcoin, PoW is used to govern the mechanics of how a new block is added to the blockchain. In the previous lesson, we learned that blockchain is append-only and once a block is added, it cannot be modified. Therefore, we need to ensure that all the honest nodes in the system will add the exact same block to their local copy of the blockchain to achieve consensus. So how does PoW achieve this? First, let’s imagine that all the nodes in the network are allowed to create a new block at anytime instantly. If this were the case, the network would get flooded with too many new blocks, and no one would be able to agree on which of the new blocks should be added to the blockchain. However, in reality, in order for a node to create a new block and broadcast that to the other nodes, it must do some computation work. The computation work is quite intensive and for bitcoin it takes roughly 10 minutes on average for any node to complete. Once a node completes this work, it broadcasts the block to other nodes who verify it. Therefore, all the nodes in the network that want to create a new block must race against each other to be the first one to complete this computation and broadcast their block. This way all the other honest nodes will receive the new block and verify that the proof of work was valid and the transactions inside the block are also correct and then add the block to their local copy of the blockchain. To read more, visit us at https://blockgeeks.com/
Views: 7840 Blockgeeks
Cryptography - defined
 
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Cryptography is the branch of mathematics that lets you create mathematical proofs that provide high levels of security. Modern cryptography is heavily based on mathematical theory and computer science practice; cryptographic algorithms are designed around computational hardness assumptions, making such algorithms hard to break in practice by any adversary. It is theoretically possible to break such a system but it is infeasible to do so by any known practical means. Reference: http://en.wikipedia.org/wiki/Cryptography Created at http://www.b2bwhiteboard.com
Views: 106 JargoTerms
CERIAS Security: Obfuscated Databases: Definitions and Constructions 6/6
 
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Clip 6/6 Speaker: Vitaly Shmatikov · University of Texas at Austin I will present some new definitions and constructions for privacy in large databases. In contrast to conventional privacy mechanisms that aim to prevent any access to individual records, our techniques are designed to prevent indiscriminate harvesting of information while enabling some forms of legitimate access. We start with a simple construction for an obfuscated database that is provably indistinguishable from a black-box lookup oracle (in the random oracle model). Some attributes of the database are designated as "key," the rest as "data." The database behaves as a lookup oracle if, for any record, it is infeasible to extract the data fields without specifying the key fields, yet, given the values of the key fields, it is easy to retrieve the corresponding data fields. We then generalize our constructions to a larger class of queries, and achieve a privacy property we call "group privacy." It ensures that users can retrieve individual records or small subsets of records from the database by identifying them precisely. The database is obfuscated in such a way that queries returning a large subset of records are computationally infeasible. This is joint work with Arvind Narayanan. For more information go to the Cerias website (http://bit.ly/dsFCBF)
Views: 53 Christiaan008
What is PSEUDORANDOM NUMBER GENERATOR? What does PSEUDORANDOM NUMBER GENERATOR mean?
 
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What is PSEUDORANDOM NUMBER GENERATOR? What does PSEUDORANDOM NUMBER GENERATOR mean? PSEUDORANDOM NUMBER GENERATOR meaning - PSEUDORANDOM NUMBER GENERATOR definition - PSEUDORANDOM NUMBER GENERATOR explanation. Source: Wikipedia.org article, adapted under https://creativecommons.org/licenses/by-sa/3.0/ license. A pseudorandom number generator (PRNG), also known as a deterministic random bit generator (DRBG), is an algorithm for generating a sequence of numbers whose properties approximate the properties of sequences of random numbers. The PRNG-generated sequence is not truly random, because it is completely determined by a relatively small set of initial values, called the PRNG's seed (which may include truly random values). Although sequences that are closer to truly random can be generated using hardware random number generators, pseudorandom number generators are important in practice for their speed in number generation and their reproducibility. PRNGs are central in applications such as simulations (e.g. for the Monte Carlo method), electronic games (e.g. for procedural generation), and cryptography. Cryptographic applications require the output not to be predictable from earlier outputs, and more elaborate algorithms, which do not inherit the linearity of simpler PRNGs, are needed. Good statistical properties are a central requirement for the output of a PRNG. In general, careful mathematical analysis is required to have any confidence that a PRNG generates numbers that are sufficiently close to random to suit the intended use. John von Neumann cautioned about the misinterpretation of a PRNG as a truly random generator, and joked that "Anyone who considers arithmetical methods of producing random digits is, of course, in a state of sin." A PRNG can be started from an arbitrary initial state using a seed state. It will always produce the same sequence when initialized with that state. The period of a PRNG is defined thus: the maximum, over all starting states, of the length of the repetition-free prefix of the sequence. The period is bounded by the number of the states, usually measured in bits. However, since the length of the period potentially doubles with each bit of "state" added, it is easy to build PRNGs with periods long enough for many practical applications. If a PRNG's internal state contains n bits, its period can be no longer than 2n results, and may be much shorter. For some PRNGs, the period length can be calculated without walking through the whole period. Linear Feedback Shift Registers (LFSRs) are usually chosen to have periods of exactly 2n-1. Linear congruential generators have periods that can be calculated by factoring. Although PRNGs will repeat their results after they reach the end of their period, a repeated result does not imply that the end of the period has been reached, since its internal state may be larger than its output; this is particularly obvious with PRNGs with a one-bit output. Most PRNG algorithms produce sequences which are uniformly distributed by any of several tests. It is an open question, and one central to the theory and practice of cryptography, whether there is any way to distinguish the output of a high-quality PRNG from a truly random sequence, knowing the algorithms used, but not the state with which it was initialized. The security of most cryptographic algorithms and protocols using PRNGs is based on the assumption that it is infeasible to distinguish use of a suitable PRNG from use of a truly random sequence. The simplest examples of this dependency are stream ciphers, which (most often) work by exclusive or-ing the plaintext of a message with the output of a PRNG, producing ciphertext. The design of cryptographically adequate PRNGs is extremely difficult, because they must meet additional criteria (see below). The size of its period is an important factor in the cryptographic suitability of a PRNG, but not the only one. A PRNG suitable for cryptographic applications is called a cryptographically secure PRNG (CSPRNG). A requirement for a CSPRNG is that an adversary not knowing the seed has only negligible advantage in distinguishing the generator's output sequence from a random sequence. In other words, while a PRNG is only required to pass certain statistical tests, a CSPRNG must pass all statistical tests that are restricted to polynomial time in the size of the seed. Though a proof of this property is beyond the current state of the art of computational complexity theory, strong evidence may be provided by reducing the CSPRNG to a problem that is assumed to be hard, such as integer factorization. In general, years of review may be required before an algorithm can be certified as a CSPRNG.
Views: 3343 The Audiopedia
Lecture - 33 Basic Cryptographic Concepts Part : II
 
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Lecture Series on Internet Technologies by Prof.I.Sengupta, Department of Computer Science & Engineering ,IIT Kharagpur. For more details on NPTEL visit http://nptel.iitm.ac.in
Views: 45327 nptelhrd
Guide : brute force password cracking tutorial  Online seo tools on bulkping for Site Seo Video
 
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Guide : brute force password cracking tutorial Online seo tools on bulkping for Site Seo Video brute, forcer, hack, crack, passwords How to hack passwords. scans every possible word and combination, this vid is for learning only please do not try hacking in any way. In cryptanalysis, a brute force attack is a method of defeating a cryptographic scheme by trying a large number of possibilities; for example, exhaustively working through all possible keys in order to decrypt a message. In most schemes, the theoretical possibility of a brute force attack is recognized, but it is set up in such a way that it would be computationally infeasible to carry out. Accordingly, one definition of "breaking" a cryptographic scheme is to find a method faster than a brute force attack. The selection of an appropriate key length depends on the practical feasibility of performing a brute force attack. By obfuscating the data to be encoded, brute force attacks are made less effective as it is more difficult to determine when one has succeeded in breaking the code. Password list, combo (user/password) list and configurable brute force modes. Highly customisable authentication sequences. Load and resume position ... I was reading another thread here where the term brute forcer was mentioned. Now, I've heard of them before, and I know what they are. ... Three types of attacks (brute-force attack, attack by an enhanced mask, enhanced dictionary-based attack); flexible, customizable search; and help. ... more BulkPing
Views: 2265 reflectiveepicuIEf
Ever wonder how Bitcoin (and other cryptocurrencies) actually work?
 
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Bitcoin explained from the viewpoint of inventing your own cryptocurrency. Home page: https://www.3blue1brown.com/ Brought to you by you: http://3b1b.co/btc-thanks And by Protocol Labs: https://protocol.ai/join/ Some people have asked if this channel accepts contributions in cryptocurrency form. Indeed! http://3b1b.co/crypto 2^256 video: https://youtu.be/S9JGmA5_unY Music by Vincent Rubinetti: https://soundcloud.com/vincerubinetti/heartbeat Here are a few other resources I'd recommend: Original Bitcoin paper: https://bitcoin.org/bitcoin.pdf Block explorer: https://blockexplorer.com/ Blog post by Michael Nielsen: https://goo.gl/BW1RV3 (This is particularly good for understanding the details of what transactions look like, which is something this video did not cover) Video by CuriousInventor: https://youtu.be/Lx9zgZCMqXE Video by Anders Brownworth: https://youtu.be/_160oMzblY8 Ethereum white paper: https://goo.gl/XXZddT If you want to contribute translated subtitles or to help review those that have already been made by others and need approval, you can click the gear icon in the video and go to subtitles/cc, then "add subtitles/cc". I really appreciate those who do this, as it helps make the lessons accessible to more people. Music by Vince Rubinetti: https://vincerubinetti.bandcamp.com/album/the-music-of-3blue1brown ------------------ 3blue1brown is a channel about animating math, in all senses of the word animate. And you know the drill with YouTube, if you want to stay posted on new videos, subscribe, and click the bell to receive notifications (if you're into that). If you are new to this channel and want to see more, a good place to start is this playlist: http://3b1b.co/recommended Various social media stuffs: Website: https://www.3blue1brown.com Twitter: https://twitter.com/3Blue1Brown Patreon: https://patreon.com/3blue1brown Facebook: https://www.facebook.com/3blue1brown Reddit: https://www.reddit.com/r/3Blue1Brown
Views: 2509408 3Blue1Brown
brute force password cracking tutorial Free seo tools on Bulkping for Site Search engine
 
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brute force password cracking tutorial Free seo tools on Bulkping for Site Search engine optimisation Movie How to hack passwords. scans every possible word and combination, this vid is for learning only please do not try hacking in any way. In cryptanalysis, a brute force attack is a method of defeating a cryptographic scheme by trying a large number of possibilities; for example, exhaustively working through all possible keys in order to decrypt a message. In most schemes, the theoretical possibility of a brute force attack is recognized, but it is set up in such a way that it would be computationally infeasible to carry out. Accordingly, one definition of "breaking" a cryptographic scheme is to find a method faster than a brute force attack. The selection of an appropriate key length depends on the practical feasibility of performing a brute force attack. By obfuscating the data to be encoded, brute force attacks are made less effective as it is more difficult to determine when one has succeeded in breaking the code. Password list, combo (user/password) list and configurable brute force modes. Highly customisable authentication sequences. Load and resume position ... I was reading another thread here where the term brute forcer was mentioned. Now, I've heard of them before, and I know what they are. ... Three types of attacks (brute-force attack, attack by an enhanced mask, enhanced dictionary-based attack); flexible, customizable search; and help. ... more BulkPing
Views: 566 betterammonia94iYB
2005-02-02 CERIAS - Obfuscated Databases: Definitions and Constructions
 
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Recorded: 02/02/2005 CERIAS Security Seminar at Purdue University Obfuscated Databases: Definitions and Constructions Vitaly Shmatikov, University of Texas at Austin I will present some new definitions and constructions for privacy in large databases. In contrast to conventional privacy mechanisms that aim to prevent any access to individual records, our techniques are designed to prevent indiscriminate harvesting of information while enabling some forms of legitimate access. We start with a simple construction for an obfuscated database that is provably indistinguishable from a black-box lookup oracle (in the random oracle model). Some attributes of the database are designated as "key," the rest as "data." The database behaves as a lookup oracle if, for any record, it is infeasible to extract the data fields without specifying the key fields, yet, given the values of the key fields, it is easy to retrieve the corresponding data fields. We then generalize our constructions to a larger class of queries, and achieve a privacy property we call "group privacy." It ensures that users can retrieve individual records or small subsets of records from the database by identifying them precisely. The database is obfuscated in such a way that queries returning a large subset of records are computationally infeasible. This is joint work with Arvind Narayanan. Vitaly Shmatikov is an assistant professor in the Department of Computer Sciences at the University of Texas at Austin. Prior to joining UT, he worked as a computer scientist at SRI International. Vitaly\'s research focuses on tools and formal methods for automated analysis and verification of secure systems, as well as various aspects of anonymity and privacy. Vitaly received his PhD in 2000 from Stanford University, with thesis on \"Finite-State Analysis of Security Protocols.\" (Visit: www.cerias.purude.edu)
Views: 67 ceriaspurdue
Cryptography | Wikipedia audio article
 
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This is an audio version of the Wikipedia Article: https://en.wikipedia.org/wiki/Cryptography 00:03:38 1 Terminology 00:07:53 2 History of cryptography and cryptanalysis 00:08:55 2.1 Classic cryptography 00:16:37 2.2 Computer era 00:19:13 2.3 Advent of modern cryptography 00:21:54 3 Modern cryptography 00:23:02 3.1 Symmetric-key cryptography 00:23:13 3.2 Public-key cryptography 00:23:28 3.3 Cryptanalysis 00:27:58 3.4 Cryptographic primitives 00:34:01 3.5 Cryptosystems 00:40:06 4 Legal issues 00:41:12 4.1 Prohibitions 00:43:02 4.2 Export controls 00:43:12 4.3 NSA involvement 00:45:45 4.4 Digital rights management 00:48:46 4.5 Forced disclosure of encryption keys 00:50:51 5 See also 00:53:36 6 References 00:55:46 7 Further reading Listening is a more natural way of learning, when compared to reading. Written language only began at around 3200 BC, but spoken language has existed long ago. Learning by listening is a great way to: - increases imagination and understanding - improves your listening skills - improves your own spoken accent - learn while on the move - reduce eye strain Now learn the vast amount of general knowledge available on Wikipedia through audio (audio article). You could even learn subconsciously by playing the audio while you are sleeping! If you are planning to listen a lot, you could try using a bone conduction headphone, or a standard speaker instead of an earphone. Listen on Google Assistant through Extra Audio: https://assistant.google.com/services/invoke/uid/0000001a130b3f91 Other Wikipedia audio articles at: https://www.youtube.com/results?search_query=wikipedia+tts Upload your own Wikipedia articles through: https://github.com/nodef/wikipedia-tts Speaking Rate: 0.8357640430680523 Voice name: en-US-Wavenet-D "I cannot teach anybody anything, I can only make them think." - Socrates SUMMARY ======= Cryptography or cryptology (from Ancient Greek: κρυπτός, translit. kryptós "hidden, secret"; and γράφειν graphein, "to write", or -λογία -logia, "study", respectively) is the practice and study of techniques for secure communication in the presence of third parties called adversaries. More generally, cryptography is about constructing and analyzing protocols that prevent third parties or the public from reading private messages; various aspects in information security such as data confidentiality, data integrity, authentication, and non-repudiation are central to modern cryptography. Modern cryptography exists at the intersection of the disciplines of mathematics, computer science, electrical engineering, communication science, and physics. Applications of cryptography include electronic commerce, chip-based payment cards, digital currencies, computer passwords, and military communications. Cryptography prior to the modern age was effectively synonymous with encryption, the conversion of information from a readable state to apparent nonsense. The originator of an encrypted message shares the decoding technique only with intended recipients to preclude access from adversaries. The cryptography literature often uses the names Alice ("A") for the sender, Bob ("B") for the intended recipient, and Eve ("eavesdropper") for the adversary. Since the development of rotor cipher machines in World War I and the advent of computers in World War II, the methods used to carry out cryptology have become increasingly complex and its application more widespread. Modern cryptography is heavily based on mathematical theory and computer science practice; cryptographic algorithms are designed around computational hardness assumptions, making such algorithms hard to break in practice by any adversary. It is theoretically possible to break such a system, but it is infeasible to do so by any known practical means. These schemes are therefore termed computationally secure; theoretical advances, e.g., improvements in integer factorization algorithms, and faster computing technology require these solutions to be continually adapted. There exist information-theoretically secure schemes that provably cannot be broken even with unlimited computing power—an example is the one-time pad—but these schemes are more difficult to use in practice than the best theoretically breakable but computationally secure mechanisms. The growth of cryptographic technology has raised a number of legal issues in the information age. Cryptography's potential for use as a tool for espionage and sedition has led many governments to classify it as a weapon and to limit or even prohibit its use and export. In some jurisdictions where the use of cryptography is legal, laws permit investigators to compel the disclosure of encryption keys for documents relevant to an investigation. Cryptography also plays a major role in digital rights management and copyright infringement of digital media.
Views: 1 wikipedia tts
The Emerging Theory of Algorithmic Fairness
 
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As algorithms reach ever more deeply into our daily lives, increasing concern that they be “fair” has resulted in an explosion of research in the theory and machine learning communities. This talk surveys key results in both areas and traces the arc of the emerging theory of algorithmic fairness. See more at https://www.microsoft.com/en-us/research/video/the-emerging-theory-of-algorithmic-fairness/
Views: 1364 Microsoft Research
TLS All the Things! - Security with Performance - Chrome Dev Summit 2014 (Chris Palmer)
 
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TLS underlies all security and privacy on the web. Chris explains how to do TLS right: not only to deploy TLS and remain performant at scale, but also demonstrating how TLS is the basis of new performance improvements.
Views: 5482 Google Developers
More Hiking in Modern Math World (2/7) - Complexity Theory, P versus NP, RSA Cryptography
 
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Learn more on http://www.science4all.org about: P versus NP: http://www.science4all.org/le-nguyen-hoang/pnp/ Divide and Conquer: http://www.science4all.org/le-nguyen-hoang/divide-and-conquer/ Probabilistic Algorithms: http://www.science4all.org/le-nguyen-hoang/probabilistic-algorithms/ Cryptography and Number Theory: http://www.science4all.org/scottmckinney/cryptography-and-number-theory/ By Lê Nguyên Hoang, Not an Ordinary Seminar, GERAD. For one hour, I will take you through some of the most amazing recent subfields of mathematics. From computational theory to chaos theory, from infinity to ergodicity, from mathematical physics to category theory, we will be unveiling mind-blowing results of modern mathematics. Although primarily aimed at non-mathematicians, it should be of great interest to everyone.
Views: 1522 Science4All (english)
Probability and Information Theory
 
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Cryptography and Network Security by Prof. D. Mukhopadhyay, Department of Computer Science and Engineering, IIT Kharagpur. For more details on NPTEL visit http://nptel.iitm.ac.in
Views: 12832 nptelhrd
24. Entanglement — QComputing, EPR, and Bell
 
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MIT 8.04 Quantum Physics I, Spring 2013 View the complete course: http://ocw.mit.edu/8-04S13 Instructor: Allan Adams In this lecture, Prof. Adams discusses the basic principles of quantum computing. No-cloning theorem and Deutsch-Jozsa algorithm are introduced. The last part of the lecture is devoted to the EPR experiment and Bell's inequality. License: Creative Commons BY-NC-SA More information at http://ocw.mit.edu/terms More courses at http://ocw.mit.edu
Views: 62886 MIT OpenCourseWare
Introduction to Crypto and CryptoCurrencies - Crypto Academy Lecture 1
 
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I am starting the new Crypto Academy so we can all learn together. Lecture 1 is an introduction to Crypto and Cryptocurrencies. In the video the lecturer will talk about Crypto Background, Hash Functions, Digital Signatures, Applications, and Basic Digital Cash. Enjoy! Thanks for watching. Subscribe and Hit that Bell Notification for all the Latest 👍👍👍 Support The Channel 👍👍👍 SubScribe Now : https://www.youtube.com/HOWHEDOIT?sub_confirmation=1 Buy Crypto @ CoinBase: https://www.coinbase.com/join/59f9eceabdc92c00d4d9a1df Track Your Taxes: https://cointracking.info?ref=M758326 Free BitCoin: https://freebitco.in/?r=13981142 (Dice Faucet) Discord With Me: https://discord.gg/8RdCcd6 Tweet With Me: https://twitter.com/BitcoinSLO Trade With Me: https://www.binance.com/?ref=16159030 ★★★ My Favorite CryptoSites ★★★ BitScreener: https://bitscreener.com/ TradingView Charts: https://www.tradingview.com/markets/cryptocurrencies/ CoinDesk News: https://www.coindesk.com/ Password Generator: (Creates Strong passes): https://passwordsgenerator.net/ 💰💰💰 Tips 💰💰💰 Donate RavenCoin [RVN]: RGQvqTGxkJMqF6opKptwuJKvWUNZohZBcu Donate DogeCoin [DOGE]: DKgESL2CPHh9BqRPa9NaSy6CczqEFgJCJQ Donate Verge [XVG]: DJgDAFd7uhdiRtGASZoNmnG6UjDJ1ifAZX ❗️❗️❗️ DISCLAIMER ❗️❗️❗️ The content in this video references an opinion and is for information and entertainment purposes only. It is not intended to be investment advice. Seek a duly licensed professional for investment advice. Edited With : Camtasia
Views: 90 HowHeDoIt
CITP Luncheon Speaker Series: Joshua Kroll – Accountable Algorithms
 
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Important decisions about people are increasingly made by algorithms: Votes are counted; voter rolls are purged; financial aid decisions are made; taxpayers are chosen for audits; air travelers are selected for enhanced search; credit eligibility decisions are made. Citizens, and society as a whole, have an interest in making these processes more transparent. Yet the full basis for these decisions is rarely available to affected people: the algorithm or some inputs may be secret; or the implementation may be secret; or the process may not be precisely described. A person who suspects the process went wrong has little recourse. And an oversight authority who wants to ensure that decisions are made according to an acceptable policy has little assurance that proffered decision rules match decisions for actual users. Traditionally, Computer Science addresses these problems by demanding a specification of the desired behavior, which can then be enforced or verified. But this model is poorly suited to real- world oversight tasks, where the specification might be complicated or might not be known in advance. For example, laws are often ambiguous precisely because it would be politically (and practically) infeasible to give a precise specification of their meaning. Instead, people do their best to approximate what they believe the law will allow and disputes about what is actually allowed happen after-the-fact via expensive investigation and adjudication (e.g. in a court or legislature). As a result, actual oversight, in which real decisions are reviewed for their correctness, fairness, or faithfulness to a rule happens only rarely, if at all. We present a novel approach to relating the tools of technology to the problem of overseeing decision making processes. Our methods use the tools of computer science to cryptographically ensure the technical properties that can be proven, while providing the necessary information so that a political, legal, or social oversight process can operate effectively. First, we present a system for the accountable execution of legal warrants, in which the decision by a judge to allow an investigator access to private or sensitive records is operationalized cryptographically, so that the investigator’s access to sensitive information is limited to only that information which the judge has explicitly allowed (and this can be confirmed by a disinterested third party). This system is an example of the current style of technical systems for accountability: a well-defined policy, specified in advance, is operationalized with technical tools. In this system, however, the goal is not just to enforce a policy, but to convince others that the policy is being enforced correctly. Second, we present accountable algorithms, unifying the tools of zero-knowledge computational integrity with cryptographic commitments to design processes that admit meaningful after-the-fact oversight, consistent with the norm in law and policy. Accountable algorithms can attest to the valid operation of a decision policy even when all or part of that policy is kept secret. As an example, consider a government tax authority that is deciding which taxpayers to audit. Taxpayers are worried that audit decisions may be based on bias or political agenda rather than legitimate criteria; or they may be worried that the authority’s code is buggy. The authority does not want to disclose the details of its decision algorithm, for fear that tax evaders will be able to avoid audits. The accountable algorithms framework will allow the tax authority to maintain the secrecy of its algorithm (in the sense that any observer learns nothing about the algorithm beyond what is conveyed by whatever input-output pairs that observer can see) while allowing each taxpayer to verify that: -the authority committed to its secret algorithm in advance, -the result asserted by the authority is the correct output of the authority’s algorithm when applied to the individual taxpayer’s data, and -the authority can reveal its algorithm to an oversight body (such as a court or legislature) for examination later, and taxpayers can verify that the revealed algorithm is the same one used to make decisions about them. Bio: Joshua A. Kroll is a PhD candidate in Computer Science at the Center for Information Technology Policy at Princeton University, where he is advised by Edward W. Felten. His research spans computer security, privacy, and the interplay between technology and public policy, with a particular focus on how to design automated processes for accountability. He received the National Science Foundation Graduate Research Fellowship in 2011
Views: 295 CITP Princeton
Cryptography
 
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Cryptography is the practice and study of techniques for secure communication in the presence of third parties . More generally, it is about constructing and analyzing protocols that overcome the influence of adversaries and which are related to various aspects in information security such as data confidentiality, data integrity, authentication, and non-repudiation. Modern cryptography intersects the disciplines of mathematics, computer science, and electrical engineering. Applications of cryptography include ATM cards, computer passwords, and electronic commerce. This video targeted to blind users. Attribution: Article text available under CC-BY-SA Creative Commons image source in video
Views: 243 encyclopediacc
Data Encryption Standard
 
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The Data Encryption Standard (DES, /ˌdiːˌiːˈɛs/ or /ˈdɛz/) is a previously predominant symmetric-key algorithm for the encryption of electronic data. It was highly influential in the advancement of modern cryptography in the academic world. Developed in the early 1970s at IBM and based on an earlier design by Horst Feistel, the algorithm was submitted to the National Bureau of Standards (NBS) following the agency's invitation to propose a candidate for the protection of sensitive, unclassified electronic government data. In 1976, after consultation with the National Security Agency (NSA), the NBS eventually selected a slightly modified version, which was published as an official Federal Information Processing Standard (FIPS) for the United States in 1977. The publication of an NSA-approved encryption standard simultaneously resulted in its quick international adoption and widespread academic scrutiny. Controversies arose out of classified design elements, a relatively short key length of the symmetric-key block cipher design, and the involvement of the NSA, nourishing suspicions about a backdoor. The intense academic scrutiny the algorithm received over time led to the modern understanding of block ciphers and their cryptanalysis. DES is now considered to be insecure for many applications. This is chiefly due to the 56-bit key size being too small; in January, 1999, distributed.net and the Electronic Frontier Foundation collaborated to publicly break a DES key in 22 hours and 15 minutes (see chronology). There are also some analytical results which demonstrate theoretical weaknesses in the cipher, although they are infeasible to mount in practice. The algorithm is believed to be practically secure in the form of Triple DES, although there are theoretical attacks. In recent years, the cipher has been superseded by the Advanced Encryption Standard (AES). Furthermore, DES has been withdrawn as a standard by the National Institute of Standards and Technology (formerly the National Bureau of Standards). This video is targeted to blind users. Attribution: Article text available under CC-BY-SA Creative Commons image source in video
Views: 1139 Audiopedia
Coding theory
 
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Coding theory is the study of the properties of codes and their fitness for a specific application. Codes are used for data compression, cryptography, error-correction and more recently also for network coding. Codes are studied by various scientific disciplines—such as information theory, electrical engineering, mathematics, linguistics, and computer science—for the purpose of designing efficient and reliable data transmission methods. This typically involves the removal of redundancy and the correction of errors in the transmitted data. This video is targeted to blind users. Attribution: Article text available under CC-BY-SA Creative Commons image source in video
Views: 383 Audiopedia
Elliptic curve cryptography
 
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Elliptic curve cryptography is an approach to public-key cryptography based on the algebraic structure of elliptic curves over finite fields. One of the main benefits in comparison with non-ECC cryptography is the same level of security provided by keys of smaller size. Elliptic curves are applicable for encryption, digital signatures, pseudo-random generators and other tasks. They are also used in several integer factorization algorithms that have applications in cryptography, such as Lenstra elliptic curve factorization. This video is targeted to blind users. Attribution: Article text available under CC-BY-SA Creative Commons image source in video
Views: 2926 Audiopedia
Digital signature
 
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A digital signature is a mathematical scheme for demonstrating the authenticity of a digital message or document. A valid digital signature gives a recipient reason to believe that the message was created by a known sender, such that the sender cannot deny having sent the message (authentication and non-repudiation) and that the message was not altered in transit (integrity). Digital signatures are commonly used for software distribution, financial transactions, and in other cases where it is important to detect forgery or tampering. This video is targeted to blind users. Attribution: Article text available under CC-BY-SA Creative Commons image source in video
Views: 235 Audiopedia
Cryptographic hash function
 
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A cryptographic hash function is a hash function which is considered practically impossible to invert, that is, to recreate the input data from its hash value alone. The input data is often called the message, and the hash value is often called the message digest or simply the digest. This video is targeted to blind users. Attribution: Article text available under CC-BY-SA Creative Commons image source in video
Views: 2397 Audiopedia
RETRY HASH FUNCTIONS RETRY
 
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This video is part of the Udacity course "Intro to Information Security". Watch the full course at https://www.udacity.com/course/ud459
Views: 159 Udacity
Design Principles - Georgia Tech - Advanced Operating Systems
 
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Watch on Udacity: https://www.udacity.com/course/viewer#!/c-ud189/l-604748923/m-619608884 Check out the full Advanced Operating Systems course for free at: https://www.udacity.com/course/ud189 Georgia Tech online Master's program: https://www.udacity.com/georgia-tech
Views: 836 Udacity
Integrating RSA SecurID token authentication with WebSeal
 
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This tutorial by Simon Stebbins explains how to integrate the IBM Security Access Manager product with RSA's token authentication solution using the WebSeal component to provide strong authentication to secure web based resources. Simon Stebbins is a software engineer for IBM and works in a development laboratory at the Gold Coast in Australia. His role is technical support for software that integrates Access Manager for Web and other IBM Security Systems products with ISV software products. He received degrees in Mathematics and Information Technology (Honours) from Queensland University of Technology, and has eight years experience in IT research and software development.
Views: 2919 IBM Developer
Birthday attack
 
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A birthday attack is a type of cryptographic attack that exploits the mathematics behind the birthday problem in probability theory. This attack can be used to abuse communication between two or more parties. The attack depends on the higher likelihood of collisions found between random attack attempts and a fixed degree of permutations. This video is targeted to blind users. Attribution: Article text available under CC-BY-SA Creative Commons image source in video
Views: 7940 Audiopedia
Computational complexity theory | Wikipedia audio article
 
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This is an audio version of the Wikipedia Article: https://en.wikipedia.org/wiki/Computational_complexity_theory 00:01:56 1 Computational problems 00:02:06 1.1 Problem instances 00:03:39 1.2 Representing problem instances 00:04:37 1.3 Decision problems as formal languages 00:05:51 1.4 Function problems 00:06:38 1.5 Measuring the size of an instance 00:06:49 2 Machine models and complexity measures 00:08:16 2.1 Turing machine 00:08:27 2.2 Other machine models 00:10:55 2.3 Complexity measures 00:12:00 2.4 Best, worst and average case complexity 00:13:36 2.5 Upper and lower bounds on the complexity of problems 00:15:25 3 Complexity classes 00:16:48 3.1 Defining complexity classes 00:17:07 3.2 Important complexity classes 00:17:16 3.3 Hierarchy theorems 00:19:26 3.4 Reduction 00:19:57 4 Important open problems 00:20:45 4.1 P versus NP problem 00:23:26 4.2 Problems in NP not known to be in P or NP-complete 00:25:36 4.3 Separations between other complexity classes 00:26:17 5 Intractability 00:26:27 6 History 00:27:51 7 See also 00:31:00 8 References 00:32:39 8.1 Citations 00:32:42 8.2 Textbooks 00:35:44 8.3 Surveys Listening is a more natural way of learning, when compared to reading. Written language only began at around 3200 BC, but spoken language has existed long ago. Learning by listening is a great way to: - increases imagination and understanding - improves your listening skills - improves your own spoken accent - learn while on the move - reduce eye strain Now learn the vast amount of general knowledge available on Wikipedia through audio (audio article). You could even learn subconsciously by playing the audio while you are sleeping! If you are planning to listen a lot, you could try using a bone conduction headphone, or a standard speaker instead of an earphone. Listen on Google Assistant through Extra Audio: https://assistant.google.com/services/invoke/uid/0000001a130b3f91 Other Wikipedia audio articles at: https://www.youtube.com/results?search_query=wikipedia+tts Upload your own Wikipedia articles through: https://github.com/nodef/wikipedia-tts "There is only one good, knowledge, and one evil, ignorance." - Socrates SUMMARY ======= Computational complexity theory focuses on classifying computational problems according to their inherent difficulty, and relating these classes to each other. A computational problem is a task solved by a computer. A computation problem is solvable by mechanical application of mathematical steps, such as an algorithm. A problem is regarded as inherently difficult if its solution requires significant resources, whatever the algorithm used. The theory formalizes this intuition, by introducing mathematical models of computation to study these problems and quantifying their computational complexity, i.e., the amount of resources needed to solve them, such as time and storage. Other measures of complexity are also used, such as the amount of communication (used in communication complexity), the number of gates in a circuit (used in circuit complexity) and the number of processors (used in parallel computing). One of the roles of computational complexity theory is to determine the practical limits on what computers can and cannot do. The P versus NP problem, one of the seven Millenium Prize Problems, is dedicated to the field of computational complexity.Closely related fields in theoretical computer science are analysis of algorithms and computability theory. A key distinction between analysis of algorithms and computational complexity theory is that the former is devoted to analyzing the amount of resources needed by a particular algorithm to solve a problem, whereas the latter asks a more general question about all possible algorithms that could be used to solve the same problem. More precisely, computational complexity theory tries to classify problems that can or cannot be solved with appropriately restricted resources. In turn, imposing restrictions on the available resources is what distinguishes computational complexity from computability theory: the latter theory asks what kind of problems can, in principle, be solved algorithmically.
Views: 6 wikipedia tts
Lecture - 38 Security
 
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Lecture series on Computer Networks by Prof.S.Ghosh, Department of Computer Science & Engineering, I.I.T.,Kharagpur. For More details on NPTEL visit http://nptel.iitm.ac.in
Views: 53935 nptelhrd
Introduction to Crypto and CryptoCurrencies - Crypto Academy Lecture 1
 
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I am starting the new Crypto Academy so we can all learn together. In the video the lecturer will talk about Crypto Background, Hash Functions, Digital Signatures, Applications, and Basic Digital Cash. Enjoy! Thanks for watching. Subscribe and Hit that Bell Notification for all the Latest 👍👍👍 Support The Channel 👍👍👍 SubScribe Now : https://www.youtube.com/HOWHEDOIT?sub... Buy Crypto @ CoinBase: https://www.coinbase.com/join/59f9ece... Track Your Taxes: https://cointracking.info?ref=M758326 Free BitCoin: https://freebitco.in/?r=13981142 (Dice Faucet) Discord With Me: https://discord.gg/8RdCcd6 Tweet With Me: https://twitter.com/BitcoinSLO Trade With Me: https://www.binance.com/?ref=16159030 ★★★ My Favorite CryptoSites ★★★ BitScreener: https://bitscreener.com/ TradingView Charts: https://www.tradingview.com/markets/c... CoinDesk News: https://www.coindesk.com/ Password Generator: (Creates Strong passes): https://passwordsgenerator.net/ 💰💰💰 Tips 💰💰💰 Donate RavenCoin [RVN]: RGQvqTGxkJMqF6opKptwuJKvWUNZohZBcu Donate DogeCoin [DOGE]: DKgESL2CPHh9BqRPa9NaSy6CczqEFgJCJQ Donate Verge [XVG]: DJgDAFd7uhdiRtGASZoNmnG6UjDJ1ifAZX ❗️❗️❗️ DISCLAIMER ❗️❗️❗️ The content in this video references an opinion and is for information and entertainment purposes only. It is not intended to be investment advice. Seek a duly licensed professional for investment advice. Edited With : Camtasia
Views: 8 CryptoSLO
Bitcoin and Anonymity - Crypto Academy Lecture 6
 
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Welcome to Crypto Academy Lecture 6. This lecture will focus on Bitcoin and Anonymity. Specific topics to include: * Anonymity basics * Overview of Bitcoin deanonymization * Mixing * Decentralized mixing * Zerocoin and Zerocash * Tor and the Silk Road Thanks for watching. Subscribe and Hit that Bell Notification for all the Latest 👍👍👍 Support The Channel 👍👍👍 SubScribe Now : https://www.youtube.com/HOWHEDOIT?sub_confirmation=1 Buy Crypto @ CoinBase: https://www.coinbase.com/join/59f9eceabdc92c00d4d9a1df Track Your Taxes: https://cointracking.info?ref=M758326 Free BitCoin: https://freebitco.in/?r=13981142 (Dice Faucet) Discord With Me: https://discord.gg/8RdCcd6 Tweet With Me: https://twitter.com/BitcoinSLO Trade With Me: https://www.binance.com/?ref=16159030 ★★★ My Favorite CryptoSites ★★★ BitScreener: https://bitscreener.com/ TradingView Charts: https://www.tradingview.com/markets/cryptocurrencies/ CoinDesk News: https://www.coindesk.com/ Password Generator: (Creates Strong passes): https://passwordsgenerator.net/ 💰💰💰 Tips 💰💰💰 Donate RavenCoin [RVN]: RGQvqTGxkJMqF6opKptwuJKvWUNZohZBcu Donate DogeCoin [DOGE]: DKgESL2CPHh9BqRPa9NaSy6CczqEFgJCJQ Donate Verge [XVG]: DJgDAFd7uhdiRtGASZoNmnG6UjDJ1ifAZX ❗️❗️❗️ DISCLAIMER ❗️❗️❗️ The content in this video references an opinion and is for information and entertainment purposes only. It is not intended to be investment advice. Seek a duly licensed professional for investment advice. Edited With : Camtasia
Views: 7 CryptoSLO
How Miners Secure Bitcoin & Blockchains (ft. Hamza, Pavlovic & Wang)
 
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This video explains the roles of the miners in blockchain management. It features Dr. Jad Hamza, Matej Pavlovic and Jingjing Wang. https://people.epfl.ch/jad.hamza https://people.epfl.ch/matej.pavlovic https://people.epfl.ch/jingjing.wang Bitcoin (ft. Rachid Guerraoui & Jad Hamza) https://www.youtube.com/watch?v=QmgVx27nA0A The Blockchain (ft. Rachid Guerraoui & Jad Hamza) https://www.youtube.com/watch?v=OzMPRAZr0-E Attacks of the Bitcoin Protocol (ft. Matej Pavlovic) https://www.youtube.com/watch?v=1sdrgDfBZog
Views: 578 ZettaBytes, EPFL

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