Patent ID: 9191199
Filing Date: 2015-11-17
Classification: H04L

Abstract:
1. A method for encrypting a message for transmission through a communication medium in encrypted form, the method comprising: receiving a public key comprising at least a first part, the first part being a representation of a transformed (n, k) linear block code with length n and dimension k over a finite field GF(p), p being a positive integer, obtainable from a private (n, k) linear block code over GF(p) by a transformation using a non-singular scrambling matrix S and a non-singular n×n matrix Q having the form wherein the matrix R is a rank-z matrix, and the matrix T is some other matrix rendering Q non-singular, the matrices S, R and T having elements in GF(p); wherein k and n are positive integers; wherein the rank-z matrix R is derived from two z×n matrices, a and b, z being a positive integer with z<n, and wherein the rank-z matrix R is a product of two z×n matrices, a and b, according to the formula R=a generating an error vector e having elements in GF(p), having a predetermined weight t; and encrypting a cleartext message represented by a cleartext vector u having elements in GF(p) to obtain a ciphertext vector x, wherein said encryption involves application of said transformed block code under use of said error vector e.