前向安全性是计算机安全领域中的一个词汇。前向安全性在数字签名中的应用。指在数字签名被破坏之前的所有签名都是正确的有效的，而不是因为某一刻的破坏使得所有的数字签名都被破坏。

In cryptography, forward secrecy (FS; also known as perfect forward secrecy) is a property of secure communication protocols in which compromise of long-term keys does not compromise past session keys. Forward secrecy protects past sessions against future compromises of secret keys or passwords. If forward secrecy is used, encrypted communications and sessions recorded in the past cannot be retrieved and decrypted should long-term secret keys or passwords be compromised in the future, even if the adversary actively interfered.