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Twisted Edwards Curve
In algebraic geometry, the twisted Edwards curves are plane models of elliptic curves, a generalisation of Edwards curves introduced by Daniel J. Bernstein, Bernstein, Birkner, Joye, Tanja Lange, Lange and Peters in 2008. The curve set is named after mathematician Harold Edwards (mathematician), Harold M. Edwards. Elliptic curves are important in public key cryptography and twisted Edwards curves are at the heart of an electronic signature scheme called EdDSA that offers high performance while avoiding security problems that have surfaced in other digital signature schemes. Definition Each twists of curves, twisted Edwards curve is a Twists of curves, twist of an Edwards curve. A twisted Edwards curve E_ over a field (mathematics), field \mathbb with \operatorname(\mathbb) \neq 2 is an wikt:affine, affine plane curve defined by the equation: : E_: a x^2+y^2= 1+dx^2y^2 where a, d are distinct non-zero elements of \mathbb. The special case a = 1 is ''untwisted'', because the curve ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Twisted Edwards Curve
In algebraic geometry, the twisted Edwards curves are plane models of elliptic curves, a generalisation of Edwards curves introduced by Daniel J. Bernstein, Bernstein, Birkner, Joye, Tanja Lange, Lange and Peters in 2008. The curve set is named after mathematician Harold Edwards (mathematician), Harold M. Edwards. Elliptic curves are important in public key cryptography and twisted Edwards curves are at the heart of an electronic signature scheme called EdDSA that offers high performance while avoiding security problems that have surfaced in other digital signature schemes. Definition Each twists of curves, twisted Edwards curve is a Twists of curves, twist of an Edwards curve. A twisted Edwards curve E_ over a field (mathematics), field \mathbb with \operatorname(\mathbb) \neq 2 is an wikt:affine, affine plane curve defined by the equation: : E_: a x^2+y^2= 1+dx^2y^2 where a, d are distinct non-zero elements of \mathbb. The special case a = 1 is ''untwisted'', because the curve ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Twists Of Curves
In the mathematics, mathematical field of algebraic geometry, an elliptic curve E over a field (mathematics), field K has an associated quadratic twist, that is another elliptic curve which is isomorphism, isomorphic to E over an algebraic closure of K. In particular, an isomorphism between elliptic curves is an isogeny of degree 1, that is an invertible isogeny. Some curves have higher order twists such as cubic and quartic twists. The curve and its twists have the same j-invariant. Applications of twists include cryptography, the solution of Diophantine equations, and when generalized to hyperelliptic curves, the study of the Sato–Tate conjecture. Quadratic twist First assume K is a field of characteristic (algebra), characteristic different from 2. Let E be an elliptic curve over K of the form: : y^2 = x^3 + a_2 x^2 +a_4 x + a_6. \, Given d\neq 0 not a square in K, the quadratic twist of E is the curve E^d, defined by the equation: : dy^2 = x^3 + a_2 x^2 + a_4 x + a_6. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Table Of Costs Of Operations In Elliptic Curves
Elliptic curve cryptography is a popular form of public key encryption that is based on the mathematical theory of elliptic curves. Points on an elliptic curve can be added and form a group under this addition operation. This article describes the computational costs for this group addition and certain related operations that are used in elliptic curve cryptography algorithms. Abbreviations for the operations The next section presents a table of all the time-costs of some of the possible operations in elliptic curves. The columns of the table are labelled by various computational operations. The rows of the table are for different models of elliptic curves. These are the operations considered : DBL - Doubling ADD - Addition mADD - Mixed addition: addition of an input that has been scaled to have ''Z''-coordinate 1. mDBL - Mixed doubling: doubling of an input that has been scaled to have ''Z'' coordinate 1. TPL - Tripling. DBL+ADD - Combined double and add step To see how addin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Affine Space
In mathematics, an affine space is a geometric structure that generalizes some of the properties of Euclidean spaces in such a way that these are independent of the concepts of distance and measure of angles, keeping only the properties related to parallelism and ratio of lengths for parallel line segments. In an affine space, there is no distinguished point that serves as an origin. Hence, no vector has a fixed origin and no vector can be uniquely associated to a point. In an affine space, there are instead ''displacement vectors'', also called ''translation'' vectors or simply ''translations'', between two points of the space. Thus it makes sense to subtract two points of the space, giving a translation vector, but it does not make sense to add two points of the space. Likewise, it makes sense to add a displacement vector to a point of an affine space, resulting in a new point translated from the starting point by that vector. Any vector space may be viewed as an affine spa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Characteristic (algebra)
In mathematics, the characteristic of a ring (mathematics), ring , often denoted , is defined to be the smallest number of times one must use the ring's identity element, multiplicative identity (1) in a sum to get the additive identity (0). If this sum never reaches the additive identity the ring is said to have characteristic zero. That is, is the smallest positive number such that: :\underbrace_ = 0 if such a number exists, and otherwise. Motivation The special definition of the characteristic zero is motivated by the equivalent definitions characterized in the next section, where the characteristic zero is not required to be considered separately. The characteristic may also be taken to be the exponent (group theory), exponent of the ring's additive group, that is, the smallest positive integer such that: :\underbrace_ = 0 for every element of the ring (again, if exists; otherwise zero). Some authors do not include the multiplicative identity element in their r ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Montgomery Curve
In mathematics the Montgomery curve is a form of elliptic curve introduced by Peter L. Montgomery in 1987, different from the usual Weierstrass form. It is used for certain computations, and in particular in different cryptography applications. Definition A Montgomery curve over a field is defined by the equation :M_: By^2 = x^3 + Ax^2 + x for certain and with . Generally this curve is considered over a finite field ''K'' (for example, over a finite field of elements, ) with characteristic different from 2 and with and , but they are also considered over the rationals with the same restrictions for and . Montgomery arithmetic It is possible to do some "operations" between the points of an elliptic curve: "adding" two points P, Q consists of finding a third one R such that R=P+Q; "doubling" a point consists of computing =P+P (For more information about operations see The group law) and below. A point P=(x,y) on the elliptic curve in the Montgomery form By^2 = x^3 + A ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Birationally Equivalent
In mathematics, birational geometry is a field of algebraic geometry in which the goal is to determine when two algebraic varieties are isomorphic outside lower-dimensional subsets. This amounts to studying mappings that are given by rational functions rather than polynomials; the map may fail to be defined where the rational functions have poles. Birational maps Rational maps A rational map from one variety (understood to be irreducible) X to another variety Y, written as a dashed arrow , is defined as a morphism from a nonempty open subset U \subset X to Y. By definition of the Zariski topology used in algebraic geometry, a nonempty open subset U is always dense in X, in fact the complement of a lower-dimensional subset. Concretely, a rational map can be written in coordinates using rational functions. Birational maps A birational map from ''X'' to ''Y'' is a rational map such that there is a rational map inverse to ''f''. A birational map induces an isomorphism from a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Affine
Affine may describe any of various topics concerned with connections or affinities. It may refer to: * Affine, a relative by marriage in law and anthropology * Affine cipher, a special case of the more general substitution cipher * Affine combination, a certain kind of constrained linear combination * Affine connection, a connection on the tangent bundle of a differentiable manifold * Affine Coordinate System, a coordinate system that can be viewed as a Cartesian coordinate system where the axes have been placed so that they are not necessarily orthogonal to each other. See tensor. * Affine differential geometry, a geometry that studies differential invariants under the action of the special affine group * Affine gap penalty, the most widely used scoring function used for sequence alignment, especially in bioinformatics * Affine geometry, a geometry characterized by parallel lines * Affine group, the group of all invertible affine transformations from any affine space over a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Field (mathematics)
In mathematics, a field is a set on which addition, subtraction, multiplication, and division are defined and behave as the corresponding operations on rational and real numbers do. A field is thus a fundamental algebraic structure which is widely used in algebra, number theory, and many other areas of mathematics. The best known fields are the field of rational numbers, the field of real numbers and the field of complex numbers. Many other fields, such as fields of rational functions, algebraic function fields, algebraic number fields, and ''p''-adic fields are commonly used and studied in mathematics, particularly in number theory and algebraic geometry. Most cryptographic protocols rely on finite fields, i.e., fields with finitely many elements. The relation of two fields is expressed by the notion of a field extension. Galois theory, initiated by Évariste Galois in the 1830s, is devoted to understanding the symmetries of field extensions. Among other results, thi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Twists Of Curves
In the mathematics, mathematical field of algebraic geometry, an elliptic curve E over a field (mathematics), field K has an associated quadratic twist, that is another elliptic curve which is isomorphism, isomorphic to E over an algebraic closure of K. In particular, an isomorphism between elliptic curves is an isogeny of degree 1, that is an invertible isogeny. Some curves have higher order twists such as cubic and quartic twists. The curve and its twists have the same j-invariant. Applications of twists include cryptography, the solution of Diophantine equations, and when generalized to hyperelliptic curves, the study of the Sato–Tate conjecture. Quadratic twist First assume K is a field of characteristic (algebra), characteristic different from 2. Let E be an elliptic curve over K of the form: : y^2 = x^3 + a_2 x^2 +a_4 x + a_6. \, Given d\neq 0 not a square in K, the quadratic twist of E is the curve E^d, defined by the equation: : dy^2 = x^3 + a_2 x^2 + a_4 x + a_6. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Algebraic Geometry
Algebraic geometry is a branch of mathematics, classically studying zeros of multivariate polynomials. Modern algebraic geometry is based on the use of abstract algebraic techniques, mainly from commutative algebra, for solving geometrical problems about these sets of zeros. The fundamental objects of study in algebraic geometry are algebraic varieties, which are geometric manifestations of solutions of systems of polynomial equations. Examples of the most studied classes of algebraic varieties are: plane algebraic curves, which include lines, circles, parabolas, ellipses, hyperbolas, cubic curves like elliptic curves, and quartic curves like lemniscates and Cassini ovals. A point of the plane belongs to an algebraic curve if its coordinates satisfy a given polynomial equation. Basic questions involve the study of the points of special interest like the singular points, the inflection points and the points at infinity. More advanced questions involve the topology of the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
EdDSA
In public-key cryptography, Edwards-curve Digital Signature Algorithm (EdDSA) is a digital signature scheme using a variant of Schnorr signature based on twisted Edwards curves. It is designed to be faster than existing digital signature schemes without sacrificing security. It was developed by a team including Daniel J. Bernstein, Niels Duif, Tanja Lange, Peter Schwabe, and Bo-Yin Yang. The reference implementation is public domain software. Summary The following is a simplified description of EdDSA, ignoring details of encoding integers and curve points as bit strings; the full details are in the papers and RFC. An EdDSA signature scheme is a choice: * of finite field \mathbb_q over odd prime power q; * of elliptic curve E over \mathbb_q whose group E(\mathbb_q) of \mathbb_q-rational points has order \#E(\mathbb_q) = 2^c \ell, where \ell is a large prime and 2^c is called the cofactor; * of base point B \in E(\mathbb_q) with order \ell; and * of cryptographic hash functi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
