Based on the simple introduction of elliptic curve encryption system, implementation of identity authentication by using elliptic curve digital signature is disscussed, and the key algorithms of identity authentication are analyzed. By making use of Ep(a,b) elliptic curve, software register is realized, meanwhile the scheme of FPGA hardware implementation is given out, and elliptic curve encryption algorithm will replace RSA algorithm gradually and it will become direction of cipher technology development in the future.