Patent ID: 8533243
Filing Date: 2013-09-10
Classification: G06F

Abstract:
1. A representation converting apparatus for public key cryptography that converts data of a set of members represented by an affine representation representing a 2r-th degree algebraic torus T 2r (F q ) (r is a prime number, and q is an integer) to data of a set of members represented by a projective representation representing a quadratic algebraic torus T 2 (F q^r ), the apparatus comprising: an acquiring unit that acquires data of a set of members of the 2r-th degree algebraic torus T a multiplying unit that performs a multiplication operation on the acquired data of the set, the multiplication operation being determined by a condition under which the set of the quadratic algebraic torus T an adding/subtracting unit that performs an addition and subtraction operation determined by the condition, the moduli, and the bases, and therefore obtains data of a set of members of the quadratic algebraic torus T an output unit that outputs the obtained set, wherein x is a member added during a quadratic extension from an extension field F the modulus of the quadratic extension is “f