In the part of cryptography which the IPSecurity protocol usually uses, the public key algorithm and symmetry encryptionalgorithm are first studied, and the widely used representative algorithms DES andRSA are analyzed.

• 在IPSec常用的密码算法部分，首先讨论了当前较为流行的对称加密算法和公开密钥算法，对其具有代表性的DES和RSA进行了深入研究。