Security Proof for Partial-Domain Hash Signature Schemes

Security Proof for Partial-Domain Hash Signature Schemes

Formal Security Proofs for a Signature Scheme with Partial Message Recovery

The Pintsov-Vanstone signature scheme with partial message recovery (PVSSR) is a variant of the Schnorr and Nyberg-Rueppel signature schemes. It produces very short signatures on messages with intrinsic redundancy. At 80 bits of security, cryptographic overhead (message expansion) ranges from 20 to 30 bytes, depending on the amount of intrinsic redundancy in the message being signed. (In compar...

Optimal Security Proofs for PSS and Other Signature Schemes

The Probabilistic Signature Scheme (PSS) designed by Bellare and Rogaway is a signature scheme provably secure against chosen message attacks in the random oracle model, whose security can be tightly related to the security of RSA. We derive a new security proof for PSS in which a much shorter random salt is used to achieve the same security level, namely we show that log2 qsig bits suffice, wh...

Philip Lafrance uWaterloo Thesis

Cryptographers and security experts around the world have been awakened to the reality that one day (potentially soon) large-scale quantum computers may be available. Most of the public-key cryptosystems employed today on the Internet, in both software and in hardware, are based on number-theoretic problems which are thought to be intractable on a classical (non-quantum) computer and hence are ...

WOTS+ - Shorter Signatures for Hash-Based Signature Schemes

We present W-OTS, a Winternitz type one-time signature scheme (W-OTS). We prove that W-OTS is strongly unforgeable under chosen message attacks in the standard model. Our proof is exact and tight. The first property allows us to compute the security of the scheme for given parameters. The second property allows for shorter signatures than previous proposals without lowering the security. This i...