第二讲第二讲 密码学及其应用密码学及其应用提纲提纲密码学的基本概念典型的加密技术 替换 一次一密 置换典型加密标准 对称密钥 分组加密 DES AES 流加密 RC4 公开密钥 RSA Diffie-Hellman 哈希与认证码 CryptographyIsA tremendous toolThe basis for many security mechanismsIs notThe solution to all security problemsReliable unless implemented properlyReliable unless used properlySomething you should try to invent yourself unless you spend a lot of time becoming an expertyou subject your design to outside reviewBasic Concepts in CryptographyEncryption scheme:functions to encrypt,decry