Signatures

• The ISignature Interface: The base signature interface.
• The SignatureFactory Class: Creating signature instances.
• The ISignatureCodec Interface: Storing signatures.
• Signature Example: Programming example.

This chapter describes the digital signature schemes implemented in GNU Crypto. The package for all signature and related classes is gnu.crypto.sig. The following signature schemes are implemented:

• DSS, the Digital Signature Standard, was standardized in 1994 by the National Institute of Standards and Technology in the Federal Information Processing Standards (FIPS) Publication 186 [FIPS186]. DSS uses the secure hash algorithm (SHA-1) internally, and produces a 160 bit signature.
• RSA-PSS. This is a digital signature scheme based on the combination of the RSA algorithm with the Probabilistic Signature Scheme (PSS) encoding scheme. RSA was invented by Ron Rivest, Adi Shamir, and Leonard Adleman; the PSS encoding was developed by Mihir Bellare and Phillip Rogaway. During efforts to adopt RSA-PSS into the IEEE P1363a standards effort, certain adaptations to the original version of RSA-PSS were made by Mihir Bellare and Phillip Rogaway and also by Burt Kaliski (the editor of IEEE P1363a) to facilitate implementation and integration into existing protocols. [JoK00]