非对称加解密理解

非对称加密有两把钥匙：公钥和私钥，成对生成。

• 公钥 --- 公开，用来加密和验证
• 私钥 --- 仅自己持有，用来解密和签名

为什么说公钥是验证而不是解密？

公钥本质上不是在解密，是在验证消息是持有私钥的发送方发来的。

1. 以 HTTPS 加解密为例

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1.2 数字签名验证流程

数字签名是为了验证身份，不是为了内容保密。
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• 原文是明文传输的，黑客拿到也没关系。这个场景只为了验证身份，不是为了内容保密。

1.3 ECDHE 密钥交换流程

这个阶段是为了交换密钥对，密钥对将来会用于对称加密。
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