The structure of a basic Whisper signature is:
typedef struct { BIGNUM *seed; BIGNUM *N; }Signature;
BIGNUM is a basic data structure used within the OpenSSL crypto library to represent large numbers. The whisper library supports these three functions using the Signature data structure:
These functions exactly map to the three whisper operations described earlier in Section 3.2.2. The main advantage of separating the whisper library from the whisper-BGP interface is modularity. The whisper library can be used in isolation with any other BGP implementation sufficiently different from the Zebra version.