|
Bar Mitzvah Attack
The bar mitzvah attack is an attack on the SSL/TLS protocols that exploits the use of the RC4 cipher with weak keys for that cipher. While this affects only the first hundred or so bytes of only the very small fraction of connections that happen to use weak keys, it allows significant compromise of user security, for example by allowing the interception of password information which could then be used for long-term exploitation. The attack uses a vulnerability in RC4 described as the ''invariance weakness'' by Fluhrer et al. in their 2001 paper on RC4 weaknesses, also known as the FMS attack.Fluhrer, S., Mantin, I., and A. Shamir,Weaknesses in the Key Scheduling Algorithm of RC4, Selected Areas of Cryptography: SAC 2001, Lecture Notes in Computer Science Vol. 2259, pp 1–24, 2001. The attack is named after the bar mitzvah ceremony which is held at 13 years of age, because the vulnerability exploited is 13 years old and likely inspired by the naming of the unrelated birthday att ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Transport Layer Security
Transport Layer Security (TLS) is a cryptographic protocol designed to provide communications security over a computer network. The protocol is widely used in applications such as email, instant messaging, and voice over IP, but its use in securing HTTPS remains the most publicly visible. The TLS protocol aims primarily to provide security, including privacy (confidentiality), integrity, and authenticity through the use of cryptography, such as the use of certificates, between two or more communicating computer applications. It runs in the presentation layer and is itself composed of two layers: the TLS record and the TLS handshake protocols. The closely related Datagram Transport Layer Security (DTLS) is a communications protocol providing security to datagram-based applications. In technical writing you often you will see references to (D)TLS when it applies to both versions. TLS is a proposed Internet Engineering Task Force (IETF) standard, first defined in 1999, and th ... [...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, if one generates a random key to encrypt a message, weak keys are 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. T ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lecture Notes In Computer Science
''Lecture Notes in Computer Science'' is a series of computer science books published by Springer Science+Business Media since 1973. Overview The series contains proceedings, post-proceedings, monographs, and Festschrifts. In addition, tutorials, state-of-the-art surveys, and "hot topics" are increasingly being included. The series is indexed by DBLP. See also *''Monographiae Biologicae'', another monograph series published by Springer Science+Business Media *''Lecture Notes in Physics'' *''Lecture Notes in Mathematics'' *''Electronic Workshops in Computing ''Electronic Workshops in Computing'' (eWiC) is a publication series by the British Computer Society. The series provides free online access for conferences and workshops in the area of computing. For example, the EVA London Conference proceeding ...'', published by the British Computer Society References External links * Publications established in 1973 Computer science books Series of non-fiction books Spring ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Birthday Attack
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 (pigeonholes). With a birthday attack, it is possible to find a collision of a hash function in \sqrt = 2^, with 2^n being the classical preimage resistance security. There is a general (though disputed) result that quantum computers can perform birthday attacks, thus breaking collision resistance, in \sqrt = 2^. Although there are some digital signature vulnerabilities associated with the birthday attack, it cannot be used to break an encryption scheme any faster than a brute-force attack. Understanding the problem As an example, consider the scenario in which a teacher with a class of 30 students (n = 30) asks for everybody's birthday (for ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fluhrer, Mantin And Shamir Attack
In cryptography, the Fluhrer, Mantin and Shamir attack is a stream cipher attack on the widely used RC4 stream cipher. The attack allows an attacker to recover the key in an RC4 encrypted stream from a large number of messages in that stream. The Fluhrer, Mantin and Shamir attack applies to specific key derivation methods, but does not apply in general to RC4-based SSL (TLS), since SSL generates the encryption keys it uses for RC4 by hashing, meaning that different SSL sessions have unrelated keys. However, the closely related bar mitzvah attack, based on the same research and revealed in 2015, does exploit those cases where weak keys are generated by the SSL keying process. Background The Fluhrer, Mantin and Shamir (FMS) attack, published in their 2001 paper "Weaknesses in the Key Scheduling Algorithm of RC4",Fluhrer, S., Mantin, I., and A. Shamir,Weaknesses in the Key Scheduling Algorithm of RC4, Selected Areas of Cryptography: SAC 2001, Lecture Notes in Computer Science Vo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
