Papers by Herman Schoenfeld
viXra, 2020
A very simple modification to the standard W-OTS scheme is presented called W-OTS# that achieves ... more A very simple modification to the standard W-OTS scheme is presented called W-OTS# that achieves a security enhancement similar to W-OTS+ but without the overhead of hashing a randomization vector in every round of the chaining function. The idea proffered by W-OTS# is to simply thwart Birthday-attacks altogether by signing an HMAC of the message-digest (keyed with cryptographically random salt) rather than the message-digest itself. The signer thwarts a birthday attack by virtue of requiring that the attacker guess the salt bits in addition to the message-digest bits during the collision scanning process. By choosing a salt length matching the message-digest length, the security of W-OTS# reduces to that of the cryptographic hash function. This essentially doubles the security level of W-OTS and facilitates the use of shorter hash functions which provide shorter and faster signatures for same security. For example, W-OTS# 128-bit signatures have commensurate security to standard W-...
Uploads
Papers by Herman Schoenfeld