RSA public keys with inside structure: Proofs of key generation and identities for web-of-trust

Abstract We propose a construction of the modulus of the RSA public keys for decentralized public-key trust generation like Web-of-Trust, where the modulus has inside structure. The first function of the structure is that it enables a peer to verify that the owner of the public key certainly generated the corresponding secret key. The second function is to tie up the public key with the owner’s identity as well as her guarantors identities. Our construction is based on the modified version of the Lenstra’s algorithm, by which a related second public key and the identity strings are embedded into the RSA modulus. The second public key is of the elliptic-curve cryptosystem (ECC) which has almost equivalent security level to the RSA cryptosystem. Our construction is applicable to a peer-to-peer network equipped with the blockchain of “consortium” and “trusted” type to yield a flat network that does not depends on PKI of the X.509 type.