1-11 Public Key ConfigurationWhen configuring public keys, go to these sections for information you are interested in:z Asymmetric Key Algorithm Overviewz Configuring the Local Asymmetric Key Pairz Configuring the Public Key of a Peerz Displaying and Maintaining Public Keysz Public Key Configuration ExamplesAsymmetric Key Algorithm OverviewBasic Conceptsz Algorithm: A set of transformation rules for encryption and decryption.z Plain text: Information without being encrypted.z Cipher text: Encrypted information.z Key: A string of characters that controls the transformation between plain text and cipher text. Itparticipates in both the encryption and decryption.Key Algorithm TypesAs shown in Figure 1-1, the information is encrypted before being sent for confidentiality. The cipher textis transmitted in the network, and then is decrypted by the receiver to obtain the original pain text.Figure 1-1 Encryption and decryptionThere are two types of key algorithms, based on whether the keys for encryption and decryption are thesame:z Symmetric key algorithm: The same key is used for both encryption and decryption. Commonlyused symmetric key algorithms include Advanced Encryption Standard (AES) and Data EncryptionStandard (DES).z Asymmetric key algorithm: Both ends have their own key pair, consisting of a private key and apublic key. The private key is kept secret while the public key may be distributed widely. Theinformation encrypted with the public key/private key can be decrypted only with the correspondingprivate key/public key; however, the private key cannot be practically derived from the public key.Asymmetric Key Algorithm ApplicationsAsymmetric key algorithms can be used for encryption/decryption and digital signature:
