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Bass-O-Matic
In cryptography, BassOmatic is the symmetric-key cipher designed by Phil Zimmermann as part of his email encryption software PGP (in the first release, version 1.0). Comments in the source code indicate that he had been designing the cipher since as early as 1988, but it was not publicly released until 1991. After Eli Biham pointed out to him several serious weaknesses in the BassOmatic algorithm over lunch at the 1991 CRYPTO conference, Zimmermann replaced it with IDEA in subsequent versions of PGP. The name is explained in this comment from the source code: "BassOmatic gets its name from an old Dan Aykroyd ''Saturday Night Live'' skit involving a blender and a whole fish. The BassOmatic algorithm does to data what the original BassOmatic did to the fish." Algorithm The algorithm operates on blocks of 256 bytes (or 2048 bits). The actual key size can be anywhere from 8 to 2048 bits. The 6 least-significant bits of the key are ''control bits'', used to choose between several ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dan Aykroyd
Daniel Edward Aykroyd ( ; born July 1, 1952) is a Canadian actor, comedian, screenwriter, and producer. Aykroyd was a writer and an original member of the "Not Ready for Prime Time Players" cast on the NBC sketch comedy series ''Saturday Night Live'' from its inception in 1975 until his departure in 1979. During his tenure on ''SNL'', he appeared in a recurring series of sketches, particularly featuring the Coneheads and the Blues Brothers. For his work on the show, he received five Primetime Emmy Award nominations, winning for Primetime Emmy Award for Outstanding Writing for a Variety Series, Outstanding Writing for a Variety Series in 1977. After his departure, he has since returned to guest roles. Aykroyd's most famous roles are as The Blues Brothers, Elwood J. Blues in ''The Blues Brothers (film), The Blues Brothers'' (1980) and ''Blues Brothers 2000'' (1998) and Ray Stantz, Dr. Raymond "Ray" Stantz in ''Ghostbusters'' (1984), and ''Ghostbusters II'' (1989) (he has reprise ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Phil Zimmermann
Philip R. Zimmermann (born 1954) is an American computer scientist and cryptographer. He is the creator of Pretty Good Privacy (PGP), the most widely used email encryption software in the world. He is also known for his work in VoIP encryption protocols, notably ZRTP and Zfone. Zimmermann is co-founder and Chief Scientist of the global encrypted communications firm Silent Circle. Background Zimmermann was born in Camden, New Jersey. He received a B.S. degree in computer science from Florida Atlantic University in Boca Raton, Florida, in 1978. In the 1980s, he worked in Boulder, Colorado, as a software engineer on the Nuclear Weapons Freeze Campaign as a military policy analyst. From 2016 to 2021, he worked at Delft University of Technology as an Associate Professor in the Cybersecurity section at the Faculty of Electrical Engineering, Mathematics, and Computer Science. PGP In 1991, he wrote the popular Pretty Good Privacy (PGP) program, and made it available (together wit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Key (cryptography)
A key in cryptography is a piece of information, usually a string of numbers or letters that are stored in a file, which, when processed through a cryptographic algorithm, can encode or decode cryptographic data. Based on the used method, the key can be different sizes and varieties, but in all cases, the strength of the encryption relies on the security of the key being maintained. A key's security strength is dependent on its algorithm, the size of the key, the generation of the key, and the process of key exchange. Scope The key is what is used to encrypt data from plaintext to ciphertext. There are different methods for utilizing keys and encryption. Symmetric cryptography Symmetric cryptography refers to the practice of the same key being used for both encryption and decryption. Asymmetric cryptography Asymmetric cryptography has separate keys for encrypting and decrypting. These keys are known as the public and private keys, respectively. Purpose Since the key ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Substitution Box
In cryptography, an S-box (substitution-box) is a basic component of symmetric key algorithms which performs substitution. In block ciphers, they are typically used to obscure the relationship between the key and the ciphertext, thus ensuring Shannon's property of confusion. Mathematically, an S-box is a nonlinear vectorial Boolean function. In general, an S-box takes some number of input bits, ''m'', and transforms them into some number of output bits, ''n'', where ''n'' is not necessarily equal to ''m''. An ''m''×''n'' S-box can be implemented as a lookup table with 2''m'' words of ''n'' bits each. Fixed tables are normally used, as in the Data Encryption Standard (DES), but in some ciphers the tables are generated dynamically from the key (e.g. the Blowfish and the Twofish encryption algorithms). Example One good example of a fixed table is the S-box from DES (S5), mapping 6-bit input into a 4-bit output: Given a 6-bit input, the 4-bit output is found by selecting the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Confusion And Diffusion
In cryptography, confusion and diffusion are two properties of a secure cipher identified by Claude Elwood Shannon, Claude Shannon in his 1945 classified report ''A Mathematical Theory of Cryptography''. These properties, when present, work together to thwart the application of statistics, and other methods of cryptanalysis. Confusion in a symmetric cipher is obscuring the local correlation between the input (plaintext), and output (ciphertext) by varying the application of the Key (cryptography), key to the data, while diffusion is hiding the plaintext statistics by spreading it over a larger area of ciphertext. Although ciphers can be confusion-only (substitution cipher, one-time pad) or diffusion-only (transposition cipher), any "reasonable" block cipher uses both confusion and diffusion. These concepts are also important in the design of cryptographic hash function, cryptographic hash functions, and pseudorandom number generators, where decorrelation of the generated values i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Permutation
In mathematics, a permutation of a set can mean one of two different things: * an arrangement of its members in a sequence or linear order, or * the act or process of changing the linear order of an ordered set. An example of the first meaning is the six permutations (orderings) of the set : written as tuples, they are (1, 2, 3), (1, 3, 2), (2, 1, 3), (2, 3, 1), (3, 1, 2), and (3, 2, 1). Anagrams of a word whose letters are all different are also permutations: the letters are already ordered in the original word, and the anagram reorders them. The study of permutations of finite sets is an important topic in combinatorics and group theory. Permutations are used in almost every branch of mathematics and in many other fields of science. In computer science, they are used for analyzing sorting algorithms; in quantum physics, for describing states of particles; and in biology, for describing RNA sequences. The number of permutations of distinct objects is factorial, us ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Key Space (cryptography)
In cryptography, key size or key length refers to the number of bits in a key used by a cryptographic algorithm (such as a cipher). Key length defines the upper-bound on an algorithm's security (i.e. a logarithmic measure of the fastest known attack against an algorithm), because the security of all algorithms can be violated by brute-force attacks. Ideally, the lower-bound on an algorithm's security is by design equal to the key length (that is, the algorithm's design does not detract from the degree of security inherent in the key length). Most symmetric-key algorithms are designed to have security equal to their key length. However, after design, a new attack might be discovered. For instance, Triple DES was designed to have a 168-bit key, but an attack of complexity 2112 is now known (i.e. Triple DES now only has 112 bits of security, and of the 168 bits in the key the attack has rendered 56 'ineffective' towards security). Nevertheless, as long as the security (understood as ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Weak Key
In cryptography, a weak key is a key, which, used with a specific cipher, makes the cipher behave in some undesirable way. Weak keys usually represent a very small fraction of the overall keyspace, which usually means that, a cipher key made by random number generation is very unlikely to give rise to a security problem. Nevertheless, it is considered desirable for a cipher to have no weak keys. A cipher with no weak keys is said to have a ''flat'', or ''linear'', key space. Historical origins Virtually all rotor-based cipher machines (from 1925 onwards) have implementation flaws that lead to a substantial number of weak keys being created. Some rotor machines have more problems with weak keys than others, as modern block and stream ciphers do. The first stream cipher machines were also rotor machines and had some of the same problems of weak keys as the more traditional rotor machines. The T52 was one such stream cipher machine that had weak key problems. The British first ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pseudorandom Number Generator
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 number generation, random numbers. The PRNG-generated sequence is not truly random, because it is completely determined by an initial value, called the PRNG's ''random seed, 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 cryptographically-secure pseudorandom number generator, elabora ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Key Schedule
In cryptography, the so-called product ciphers are a certain kind of cipher, where the (de-)ciphering of data is typically done as an iteration of '' rounds''. The setup for each round is generally the same, except for round-specific fixed values called a round constant, and round-specific data derived from the cipher key called a round key. A key schedule is an algorithm that calculates all the round keys from the key. Some types of key schedules *Some ciphers have simple key schedules. For example, the block cipher TEA splits the 128-bit key into four 32-bit pieces and uses them repeatedly in successive rounds. * DES has a key schedule in which the 56-bit key is divided into two 28-bit halves; each half is thereafter treated separately. In successive rounds, both halves are rotated left by one or two bits (specified for each round), and then 48 round key bits are selected by Permuted Choice 2 (PC-2) – 24 bits from the left half and 24 from the right. The rotations h ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Saturday Night Live
''Saturday Night Live'' (''SNL'') is an American Late night television in the United States, late-night live television, live sketch comedy variety show created by Lorne Michaels and developed by Michaels and Dick Ebersol that airs on NBC. The show's premiere was hosted by George Carlin on NBC on October 11, 1975, under the original title ''NBC's Saturday Night''. The show's comedy sketches, which often parody popular culture and politics, are performed by a Saturday Night Live cast members, large and varying cast of repertory and newer cast members. Each episode is hosted by a celebrity guest, who usually delivers the opening monologue and performs in sketches with the cast, with featured performances by a musical guest. An episode normally begins with a cold open sketch that is usually based on current events and ends with someone breaking character and proclaiming, "Live from New York, it's Saturday Night!, Live from New York, it's ''Saturday Night''!", properly beginning the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Key Size
In cryptography, key size or key length refers to the number of bits in a key used by a cryptographic algorithm (such as a cipher). Key length defines the upper-bound on an algorithm's security (i.e. a logarithmic measure of the fastest known attack against an algorithm), because the security of all algorithms can be violated by brute-force attacks. Ideally, the lower-bound on an algorithm's security is by design equal to the key length (that is, the algorithm's design does not detract from the degree of security inherent in the key length). Most symmetric-key algorithms are designed to have security equal to their key length. However, after design, a new attack might be discovered. For instance, Triple DES was designed to have a 168-bit key, but an attack of complexity 2112 is now known (i.e. Triple DES now only has 112 bits of security, and of the 168 bits in the key the attack has rendered 56 'ineffective' towards security). Nevertheless, as long as the security (understood ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
