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PBKDF1
In cryptography, PBKDF1 and PBKDF2 (Password-Based Key Derivation Function 1 and 2) are key derivation functions with a sliding computational cost, used to reduce vulnerabilities of brute-force attacks. PBKDF2 is part of RSA Laboratories' Public-Key Cryptography Standards (PKCS) series, specifically PKCS#5 v2.0, also published as Internet Engineering Task Force's RFC2898. It supersedes PBKDF1, which could only produce derived keys up to 160 bits long. RFC8018 (PKCS#5 v2.1), published in 2017, recommends PBKDF2 for password hashing. Purpose and operation PBKDF2 applies a pseudorandom function, such as hash-based message authentication code (HMAC), to the input password or passphrase along with a salt value and repeats the process many times to produce a ''derived key'', which can then be used as a cryptographic key in subsequent operations. The added computational work makes password cracking much more difficult, and is known as key stretching. When the standard was written ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Independent Politician
An independent or non-partisan politician is a politician not affiliated with any political party or bureaucratic association. There are numerous reasons why someone may stand for office as an independent. Some politicians have political views that do not align with the platforms of any political party, and therefore choose not to affiliate with them. Some independent politicians may be associated with a party, perhaps as former members of it, or else have views that align with it, but choose not to stand in its name, or are unable to do so because the party in question has selected another candidate. Others may belong to or support a political party at the national level but believe they should not formally represent it (and thus be subject to its policies) at another level. In running for public office, independents sometimes choose to form a party or alliance with other independents, and may formally register their party or alliance. Even where the word "independent" is used, s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rainbow Tables
A rainbow table is an efficient way to store data that has been computed in advance to facilitate cracking passwords. To protect stored passwords from compromise in case of a data breach, organizations avoid storing them directly, instead transforming them using a scrambling function – typically a cryptographic hash. One line of attack against this protection is to precompute the hashes of likely or possible passwords, and then store them in a dataset. However, such a dataset can become too big as the range of possible passwords grows. Rainbow tables address this problem by storing chains of possible passwords to save space. Undoing the chains takes significant computation time, but overall this tradeoff makes certain classes of attacks practical. Rainbow tables partition a function (the hash), whose domain is a set of values and whose codomain is a set of keys derived from those values, into chains such that each chain is an alternating sequence of values and keys, followed by ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Password Authentication
A password, sometimes called a passcode (for example in Apple devices), is secret data, typically a string of characters, usually used to confirm a user's identity. Traditionally, passwords were expected to be memorized, but the large number of password-protected services that a typical individual accesses can make memorization of unique passwords for each service impractical. Using the terminology of the NIST Digital Identity Guidelines, the secret is held by a party called the ''claimant'' while the party verifying the identity of the claimant is called the ''verifier''. When the claimant successfully demonstrates knowledge of the password to the verifier through an established authentication protocol, the verifier is able to infer the claimant's identity. In general, a password is an arbitrary string of characters including letters, digits, or other symbols. If the permissible characters are constrained to be numeric, the corresponding secret is sometimes called a personal i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
List Of PBKDF2 Implementations
List of software that implements or uses the PBKDF2 key derivation standard. Implementations * wolfSSL * LibgcryptBash implementation [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Password Policy
A password policy is a set of rules designed to enhance computer security by encouraging users to employ strong passwords and use them properly. A password policy is often part of an organization's official regulations and may be taught as part of security awareness training. Either the password policy is merely advisory, or the computer systems force users to comply with it. Some governments have national authentication frameworks that define requirements for user authentication to government services, including requirements for passwords. NIST guidelines The United States Department of Commerce's National Institute of Standards and Technology (NIST) has put out two standards for password policies which have been widely followed. 2004 From 2004, the “NIST Special Publication 800-63. Appendix A,” advised people to use irregular capitalization, special characters, and at least one numeral. This was the advice that most systems followed, and was "baked into" a number of standa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Balloon Hashing
Balloon hashing is a key derivation function presenting proven memory-hard password-hashing and modern design. It was created by Dan Boneh, Henry Corrigan-Gibbs (both at Stanford University) and Stuart Schechter (Microsoft Research) in 2016. It is a recommended function in NIST password guidelines. The authors claim that Balloon: * has ''proven'' memory-hardness properties, * is built from standard primitives: it can use any standards non-space-hard cryptographic hash function as a sub-algorithm (e.g., SHA-3, SHA-512), * is resistant to side-channel attacks: the memory access pattern is independent of the data to be hashed, * is easy to implement and matches the performance of similar algorithms. Balloon is compared by its authors with Argon2, a similarly performing algorithm. Algorithm There are three steps in the algorithm: # Expansion, where an initial buffer is filled with a pseudorandom A pseudorandom sequence of numbers is one that appears to be statistically rando ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lyra2
Lyra2 is a password hashing scheme (PHS) that can also work as a key derivation function (KDF). It received a special recognition during the Password Hashing Competition in July 2015, which was won by Argon2. Besides being used for its original purposes, it is also in the core of proof-of-work algorithms such as Lyra2REv2, adopted by Vertcoin, MonaCoin, among other cryptocurrencies Lyra2 was designed by Marcos A. Simplicio Jr., Leonardo C. Almeida, Ewerton R. Andrade, Paulo C. F. dos Santos, and Paulo S. L. M. Barreto from Escola Politécnica da Universidade de São Paulo. It is an improvement over Lyra, previously proposed by the same authors. Lyra2 preserves the security, efficiency and flexibility of its predecessor, including: (1) the ability to configure the desired amount of memory, processing time and parallelism to be used by the algorithm; and (2) the capacity of providing a high memory usage with a processing time similar to that obtained with scrypt. In addition, it brin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Argon2
Argon2 is a key derivation function that was selected as the winner of the 2015 Password Hashing Competition. It was designed by Alex Biryukov, Daniel Dinu, and Dmitry Khovratovich from the University of Luxembourg. The reference implementation of Argon2 is released under a Creative Commons CC0 license (i.e. public domain) or the Apache License 2.0, and provides three related versions: *Argon2d maximizes resistance to GPU cracking attacks. It accesses the memory array in a password dependent order, which reduces the possibility of time–memory trade-off (TMTO) attacks, but introduces possible side-channel attacks. *Argon2i is optimized to resist side-channel attacks. It accesses the memory array in a password independent order. *Argon2id is a hybrid version. It follows the Argon2i approach for the first half pass over memory and the Argon2d approach for subsequent passes. The RFC recommends using Argon2id if you do not know the difference between the types or you consider side ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Password Hashing Competition
The Password Hashing Competition was an open competition announced in 2013 to select one or more password hash functions that can be recognized as a recommended standard. It was modeled after the successful Advanced Encryption Standard process and NIST hash function competition, but directly organized by cryptographers and security practitioners. On 20 July 2015, Argon2 was selected as the final PHC winner, with special recognition given to four other password hashing schemes: Catena, Lyra2, yescrypt and Makwa. One goal of the Password Hashing Competition was to raise awareness of the need for strong password hash algorithms, hopefully avoiding a repeat of previous password breaches involving weak or no hashing, such as the ones involving RockYou (2009), JIRA, Gawker (2010), PlayStation Network outage, Battlefield Heroes (2011), eHarmony, LinkedIn, Adobe, ASUS, South Carolina Department of Revenue (2012), Evernote, Ubuntu Forums (2013), etc. Danielle Walker"Black Hat: Crackable ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Scrypt
In cryptography, scrypt (pronounced "ess crypt") is a password-based key derivation function created by Colin Percival in March 2009, originally for the Tarsnap online backup service. The algorithm was specifically designed to make it costly to perform large-scale custom hardware attacks by requiring large amounts of memory. In 2016, the scrypt algorithm was published by IETF as RFC 7914. A simplified version of scrypt is used as a proof-of-work scheme by a number of cryptocurrencies, first implemented by an anonymous programmer called ArtForz in Tenebrix and followed by Fairbrix and Litecoin soon after. Introduction A password-based key derivation function (password-based KDF) is generally designed to be computationally intensive, so that it takes a relatively long time to compute (say on the order of several hundred milliseconds). Legitimate users only need to perform the function once per operation (e.g., authentication), and so the time required is negligible. However ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bcrypt
bcrypt is a password-hashing function designed by Niels Provos and David Mazières, based on the Blowfish cipher and presented at USENIX in 1999. Besides incorporating a salt to protect against rainbow table attacks, bcrypt is an adaptive function: over time, the iteration count can be increased to make it slower, so it remains resistant to brute-force search attacks even with increasing computation power. The bcrypt function is the default password hash algorithm for OpenBSD and was the default for some Linux distributions such as SUSE Linux. There are implementations of bcrypt in C, C++, C#, Embarcadero Delphi, Elixir, Go, Java, JavaScript, Perl, PHP, Python, Ruby, and other languages. Background Blowfish is notable among block ciphers for its expensive key setup phase. It starts off with subkeys in a standard state, then uses this state to perform a block encryption using part of the key, and uses the result of that encryption (which is more accurate at hashing) to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Colin Percival
Colin A. Percival (born 1980) is a Canadian computer scientist and computer security researcher. He completed his undergraduate education at Simon Fraser University and a doctorate at the University of Oxford. While at university he joined the FreeBSD project, and achieved some notoriety for discovering a security weakness in Intel's hyper-threading technology. Besides his work in delta compression and the introduction of memory-hard functions, he is also known for developing the Tarsnap online backup service, which became his full-time job. Education Percival began taking mathematics courses at Simon Fraser University (SFU) at age 13, as a student at Burnaby Central Secondary School. He graduated from Burnaby Central and officially enrolled at SFU in 1998. At SFU he studied number theory under Peter Borwein, and competed in the William Lowell Putnam Mathematical Competition, placing in the top 15 in 1998 and as a Putnam Fellow (in the top six) in 1999. From 1998 to 2000 he ran t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
