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密钥预分配
工具包中的每种密码都假设密钥已就位，而将密钥送达才是问题的困难所在。公钥通过证书将身份绑定到密钥——证书是认证机构对该绑定的签名声明，任何信任该机构的人都可验证，并可链式构成层次结构；去中心化的信任网则是草根式的替代方案。私钥面临更严峻的数量问题：每对实体需要一把密钥，因此密钥分发中心为每个参与者持有一把主密钥，并按需生成会话密钥；Diffie-Hellman密钥交换让两个陌生人通过模幂运算和离散对数问题的困难性在公开信道上推导出共享密钥，但若无认证，它只回答了问题的一半。
1. Binding Names to Keys
Binding Names to Keys
2. One Key per Pair
One Key per Pair
3. Choosing Among the Three
Choosing Among the Three
4. A Secret From Public Exchange
A Secret From Public Exchange
5. The certificate's claim
What exactly does a public key certificate assert?
6. Walking the chain
A browser knows only a set of root keys. How does it come to trust a website's certificate?
7. The quadratic problem
Why is predistributing secret keys harder than predistributing public keys?
8. The ticket
In a KDC exchange, what does the ticket Alice carries to Bob contain?
9. The discrete log's protection
An eavesdropper sees and in a Diffie-Hellman exchange. What protects the shared secret?
10. The man in the middle
Why is raw Diffie-Hellman insufficient on its own against an active attacker?
11. The signed binding
What is the digitally signed statement binding a public key to an identity called?
12. The grass-roots alternative
What decentralized trust model has users sign the keys of people they have verified, with no authorities at all?
13. The trusted mint
What centralized service shares a master key with every participant and mints session keys on request?
14. The hard inverse
Diffie-Hellman's security rests on the difficulty of computing exponents from powers modulo a prime, known as what problem?