特点：
突破了目前公钥密码体制的单一公钥/私钥对。可以使用多组密钥解密相同内容，不增加密文数据长度
用160bit密钥相当于RSA1024的安全强度 10^11 MIPS Years
Key Pair生成快，3.8ms vs 4000ms+ (160bit ECC vs 1024bit RSA)
复用代码：
lip.c
lip.h
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Free-LIP v1.0
Signed arbitrary length long int package.
Copyright Arjen K. Lenstra, 1989
sha256.c
sha256.h
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An implementation of the SHA-256 hash function.
Tom St Denis, Oct 12th 2000
onb.c
onb_integer.c
------------------------------------------------------------
Optimal Normal Basis and implement combinations of
math packages to create advanced protocols.
Mike Rosing, Jan 4, 1998
