# TLS(Transport Layer Security)

### TLS(Transport Layer Security), base on TCP, build from SSL(Secure Socket Layer).

#### 1\. Why?

> 应用层的报文明文传输，存在安全性,可靠性问题，所以在应用层和传输层中间加上SSL/TSL协议

#### 2\. What?

> 保密(message privacy)
> 完整性(message integrity)
> 认证(mutual authentication)