| 摘要 |
<p>The invention provides for a cryptographic method for digital signature. A set S1 of k polynomial functions Pk(x1, ..., xn+v, y1, ..., y¿k¿) are supplied as a public key, where k, v, and n are integers, x¿1?, ..., xn+v are n+v variables of a first type, and y1, .., yk are k variables of a second type, the set S1 being obtained by applying a secret key operation on a given set S2 of k polynomial functions P'k(a1, ..., an+v, y1, ..., yk), a1, ..., an+v designating n+v variables including a set of n 'oil' and v 'vinegar' variables. A message to be signed is provided and submitted to a hash function to produce a series of k values b1, ..., bk. These k values are substituted for the k variables y1, ...,yk, of the set S2 to produce a set S3 of k polynomial functions P''k(a1, ..., an+v), and v values a'n+1, ..., a'n+v are selected for the v 'vinegar' variables. A set of equations P''k(a1, ..., a'n+v)=0 is solved to obtain a solution for a'1, ..., a'n and the secret key operation is applied to transform the solution to the digital signature.</p> |
