Digital Signature Algorithm (DSA)
"In DSA, signature generation is faster than signature verification, whereas with the RSA algorithm, signature verification is very much faster than signature generation (if the public and private exponents, respectively, are chosen for this property, which is the usual case). It might be claimed that it is advantageous for signing to be the faster operation, but since in many applications a piece of digital information is signed once, but verified often, it may well be more advantageous to have faster verification."
"David Kravitz, former member of the NSA, holds a patent on DSA. Claus P. Schnorr has asserted that his patent covers certain implementations of DSA. RSA Security has also asserted coverage of certain implementations of DSA by the Schnorr patent." more
- Is DSA Secure? - this document basically says "barring something we don't know about - its secure."