FIELD: information technology.
SUBSTANCE: authentication device, which includes a key storage module for storing L(L≥2) secret keys si(i = 1 to L) and L public keys yi, which satisfy the condition yi=F(si) with respect to a set F of polynomials of multiple variables of the n-th order (n≥2), and a module for executing an interactive protocol, designed for performing, using a verification interactive protocol, verification of the value of (L-1) secret keys si, which satisfy the condition yi=F(si). The module for executing the interactive protocol includes a call receiving module for receiving L calls Chi from the verifier; a call selection module for arbitrary selection of (L-1) calls Chi from L calls Chi, received by the call receiving module; a response generating module for generating, using the secret keys si, (L-1) responses Rspi, respectively, for L-1) calls Chi selected by the call selection module, and a response transmitting module for transmitting to the verifier (L-1) responses Rspi generated by the response generating module.
EFFECT: effective protection of a digital signature.
8 cl, 21 dwg
