SECCURE Elliptic Curve Crypto Utility for Reliable Encryption http://point-at-infinity.org/seccure/ seccure builds on a bunch of cryptographic algorithms and techniques (a comprehensive list is presented below). To my best knowledge none of these and in particular no part of seccure is covered by patents. - ECIES, ECDSA, ECDH - AES256, SHA256, SHA512, CTR Mode, HMAC Mode - Point compression on elliptic curves over prime fields - Point multiplication using Double-And-Add-Algorithm (may be replaced by a NAF-Algorithm in the future) Note: Diffie-Hellman key agreement actually has been patented in 1977. The patent expired regularly in 1997. Note: some of the supported elliptic curves are defined over prime fields with moduli of "Crandall type" (which may be patented). Seccure doesn't make use of the special structure these primes offer and therefore doesn't touch the Crandall patents.