Chapter 4 - key management and distribution

1. Key lifetime ： produce 、 Storage 、 Distribute 、 Use 、 to update 、 revoke 、 The destruction
2. Secret key classification
   Primary secret key ： Encryption and decryption data .
   Second level secret key ： Secret key encryption secret key , Protect the primary secret key .
   Master key ： Protect the secondary secret key .
3. Secret key distribution technology ： Direct distribution 、 Key distribution center mode 、Diffie-Hellman Method 、 Hierarchical secret key assignment
4. Key distribution center mode
   technological process ：KDC( Key distribution center ) Share a second level with each user ( Secret key encryption ) Secret key , The user to KDC Request session key ,KDC Generate session key ,KDC Use the secret key to encrypt the session secret key and distribute it to the user
   advantage ： The user does not save the work key , One report and one secret can be realized
   shortcoming ： Large traffic , Better identification function is required , To identify KDC And the user
5. Public key cryptosystem allocates secret keys
   (1) towards B Send the generated public key and A The identity of the
   (2)B After receiving the message , Generate session key Ks, Add... With public key Pass the secret to A
   (3)A Decrypt with the private key to get Ks problem ： May be passed off as
6. Public key management solution
   Public key disclosure ： No need for confidentiality , The list must be complete
   Bind the public key to the identity
   Guaranteed by a trusted third party
   Other user authentication certificates
7. Public key certificate ： Users exchange their public keys through public key certificates
   data structure ： User ID 、 Public key 、CA Signature
   
   Certificate type ： In terms of use ： Signing certificate and encryption certificate
   From the perspective of end users ： System certificate and user certificate
8. PKI— Public key infrastructure ： An infrastructure established to manage public keys and certificates .
   PKI Logical structure of
   
9. Certification body （CA）： Be responsible for issuing user secret keys or certificates 、 to update 、 abolish 、 Certification and other management work , Divided into public CA And private CA
10. CA function ： Issue certificate 、 Annulment certificate 、 Certificate update 、 Certificate authentication and secret key management .
11. PKI Architecture of : single CA structure 、 level CA structure 、 cross CA structure