From Fixed-Length Messages to Arbitrary-Length Messages Practical RSA Signature Padding Schemes

摘要

We show how to construct a practical secure signature padding scheme for arbitrarily long messages from a secure signature padding scheme for fixed-length messages. This new construction is based on a one-way compression function respecting the division intractability assumption. By practical, we mean that our scheme can be instantiated using dedicated compression functions and without chaining. This scheme also allows precomputations on partially received messages. Finally, we give an instantiation of our scheme using SHA-1 and PKCS #1 ver. 1.5.