===================== MessageDigest=====================
产生消息摘要的流程
===================== Signature=====================
对数据进行签名和签名校验的流程
===================== Ciper =====================
加密和解密的流程:
A,Symmetric vs. Asymmetric Cryptography
Symmetric:双方保存同一份密钥。即此份密钥绝对不能泄露
Asymmetric Cryptography:一人保存私钥,其他人保存公钥,私钥绝对不能泄露
B,Stream vs. Block Ciphers
Stream:针对流加密,不需要填充
Block Ciphers:针对块加密,如果不足一块,需要填充,填充模式例如:PKCS5PADDING
C,当加密用Block Ciphers还会涉及到加密模式:
CBC (Cipher Block Chaining),
CFB (Cipher Feedback Mode),
OFB (Output Feedback Mode).
ECB (Electronic Cookbook Mode)
四种加密模式详见:http://www.cnblogs.com/happyhippy/archive/2006/12/23/601353.html
===================== KeyFactory =====================
在Key 和 KeySpec之间做转换的:
===================== SecretKeyFactory =====================
===================== KeyPairGenerator =====================
===================== KeyGenerator =====================
===================== KeyAgreement =====================