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GGH Signature Scheme
The Goldreich-Goldwasser-Halevi (GGH) signature scheme is a digital signature scheme proposed in 1995 and published in 1997, based on solving the closest vector problem (CVP) in a lattice. The signer demonstrates knowledge of a good basis for the lattice by using it to solve CVP on a point representing the message; the verifier uses a bad basis for the same lattice to verify that the signature under consideration is actually a lattice point and is sufficiently close to the message point. The idea was not developed in detail in the original paper, which focussed more on the associated encryption algorithm. GGH signatures form the basis for the NTRUSign NTRUSign, also known as the NTRU Signature Algorithm, is an NTRU public-key cryptography digital signature algorithm based on the GGH signature scheme. The original version of NTRUSign was Polynomial Authentication and Signature Scheme (PASS), an ... signature algorithm. and Oded Regev had cryptanalyzed ( broken) the original GG ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Digital Signature
A digital signature is a mathematical scheme for verifying the authenticity of digital messages or documents. A valid digital signature, where the prerequisites are satisfied, gives a recipient very high confidence that the message was created by a known sender (authenticity), and that the message was not altered in transit (integrity). Digital signatures are a standard element of most cryptographic protocol suites, and are commonly used for software distribution, financial transactions, contract management software, and in other cases where it is important to detect forgery or tampering. Digital signatures are often used to implement electronic signatures, which includes any electronic data that carries the intent of a signature, but not all electronic signatures use digital signatures. [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Closest Vector Problem
In computer science, lattice problems are a class of Mathematical optimization, optimization problems related to mathematical objects called Lattice (group), lattices. The conjectured intractability of such problems is central to the construction of secure Lattice-based cryptography, lattice-based cryptosystems: Lattice problems are an example of NP-hardness, NP-hard problems which have been shown to be Computational hardness assumption, average-case hard, providing a test case for the security of cryptographic algorithms. In addition, some lattice problems which are worst-case hard can be used as a basis for extremely secure cryptographic schemes. The use of worst-case hardness in such schemes makes them among the very few schemes that are very likely secure even against quantum computers. For applications in such cryptosystems, lattices over vector space (often \mathbb^n) or free modules (often \mathbb^n) are generally considered. For all the problems below, assume that we are g ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lattice (group)
In geometry and group theory, a lattice in the real coordinate space \mathbb^n is an infinite set of points in this space with the properties that coordinate wise addition or subtraction of two points in the lattice produces another lattice point, that the lattice points are all separated by some minimum distance, and that every point in the space is within some maximum distance of a lattice point. Closure under addition and subtraction means that a lattice must be a subgroup of the additive group of the points in the space, and the requirements of minimum and maximum distance can be summarized by saying that a lattice is a Delone set. More abstractly, a lattice can be described as a free abelian group of dimension n which spans the vector space \mathbb^n. For any basis of \mathbb^n, the subgroup of all linear combinations with integer coefficients of the basis vectors forms a lattice, and every lattice can be formed from a basis in this way. A lattice may be viewed as a regula ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
GGH Encryption Algorithm
The Goldreich–Goldwasser–Halevi (GGH) lattice-based cryptosystem is an asymmetric cryptosystem based on lattices. There is also a GGH signature scheme. The Goldreich–Goldwasser–Halevi (GGH) cryptosystem makes use of the fact that the closest vector problem can be a hard problem. This system was published in 1997 by Oded Goldreich, Shafi Goldwasser, and Shai Halevi, and uses a trapdoor one-way function which relies on the difficulty of lattice reduction. The idea included in this trapdoor function is that, given any basis for a lattice, it is easy to generate a vector which is close to a lattice point, for example taking a lattice point and adding a small error vector. But to return from this erroneous vector to the original lattice point a special basis is needed. The GGH encryption scheme was cryptanalyzed (broken) in 1999 by . Nguyen and Oded Regev had cryptanalyzed the related GGH signature scheme in 2006. Operation GGH involves a ''private key'' and a ''public ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
NTRUSign
NTRUSign, also known as the NTRU Signature Algorithm, is an NTRU public-key cryptography digital signature algorithm based on the GGH signature scheme. The original version of NTRUSign was Polynomial Authentication and Signature Scheme (PASS), and was published at CrypTEC'99. The improved version of PASS was named as NTRUSign, and was presented at the rump session of Asiacrypt 2001 and published in peer-reviewed form at the RSA Conference 2003. The 2003 publication included parameter recommendations for 80-bit security. A subsequent 2005 publication revised the parameter recommendations for 80-bit security, presented parameters that gave claimed security levels of 112, 128, 160, 192 and 256 bits, and described an algorithm to derive parameter sets at any desired security level. NTRU Cryptosystems, Inc. have applied for a patent on the algorithm. NTRUSign involves mapping a message to a random point in 2''N''-dimensional space, where ''N'' is one of the NTRUSign parameters, and s ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oded Regev (computer Scientist)
Oded Regev (Hebrew: עודד רגב) is an Israeli-American theoretical computer scientist and mathematician. He is a professor of computer science at the Courant institute at New York University. He is best known for his work in lattice-based cryptography, and in particular for introducing the learning with errors problem. Biography Oded Regev earned his B.Sc. in 1995, M.Sc. in 1997, and Ph.D. in 2001, all from Tel Aviv University. He completed his Ph.D. at the age of 21, advised by Yossi Azar, with a thesis titled "Scheduling and Load Balancing." He held faculty positions at Tel Aviv University and the École Normale Supérieure before joining the Courant institute. Work Regev has done extensive work on lattices. He is best known for introducing the learning with errors problem (LWE), for which he won the 2018 Gödel Prize. As the citation reads: Regev’s work has ushered in a revolution in cryptography, in both theory and practice. On the theoretical side, LWE has serv ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Broken Cipher
In cryptography, security level is a measure of the strength that a cryptographic primitive — such as a cipher or hash function — achieves. Security level is usually expressed as a number of "bits of security" (also security strength), where ''n''-bit security means that the attacker would have to perform 2''n'' operations to break it, but other methods have been proposed that more closely model the costs for an attacker. This allows for convenient comparison between algorithms and is useful when combining multiple primitives in a hybrid cryptosystem, so there is no clear weakest link. For example, AES-128 (key size 128 bits) is designed to offer a 128-bit security level, which is considered roughly equivalent to a RSA using 3072-bit key. In this context, security claim or target security level is the security level that a primitive was initially designed to achieve, although "security level" is also sometimes used in those contexts. When attacks are found that have ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Digital Signature Schemes
Digital usually refers to something using discrete digits, often binary digits. Technology and computing Hardware *Digital electronics, electronic circuits which operate using digital signals **Digital camera, which captures and stores digital images ***Digital versus film photography **Digital computer, a computer that handles information represented by discrete values **Digital recording, information recorded using a digital signal Socioeconomic phenomena *Digital culture, the anthropological dimension of the digital social changes *Digital divide, a form of economic and social inequality in access to or use of information and communication technologies *Digital economy, an economy based on computing and telecommunications resources Other uses in technology and computing *Digital data, discrete data, usually represented using binary numbers *Digital marketing, search engine & social media presence booster, usually represented using online visibility. *Digital media, media sto ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
