Protection of signatures based on the problem of the logarithm discrete

摘要

The present invention relates to the generation reliable form of a digital signature s = (r, s) of a message m, at low cost, dsa type, and ec - sad. In a known manner, the components of the signature are determined with the aid of a random integer k, of a point g, of a private key det a hash m of the message m. according to the invention, the determination of the second component of the signature s comprises: mask the first component of the signature r or the private key of the random integer k with the aid of a modular addition; multiplying the result of the masking with the other value r or d; and to add, to the result of multiplication, optionally modified, a multiple not - zero, positive or negative, the said second value r or d. in the case of the american the so-called "signature ", the second component can be calculated according to the following formula: s = k - 1. (m + r (ω) - (r * d).