Optimized C library for ECDSA signatures and secret/public key
operations on curve secp256k1.

This library is intended to be the highest quality publicly available
library for cryptography on the secp256k1 curve. However, the primary
focus of its development has been for usage in the Bitcoin system
and usage unlike Bitcoin's may be less well tested, verified, or
suffer from a less well thought out interface. Correct usage requires
some care and consideration that the library is fit for your
application's purpose.
