Table 5. Cisco Aironet 1140 Series Power Injector Product Numbers Product Number Product Description AIR-PWRINJ4= Cisco Aironet Power Injector for the 1140 Series (Spare) Power Supply A Cisco Aironet power supply is not included with the Cisco Aironet 1140 Series and may be purchased separately (Table 6). The AIR-PWR-B is the recommended power supply for the 1140 Series.
public-key encryption. Related Terms. A cryptographic system that uses two keys -- a public key known to everyone and a private or secret key known only to the recipient of the message. When John wants to send a secure message to Jane, he uses Jane's public key to encrypt the message. Jane then uses her private key to decryptit.
The keys, in practice, represent a shared secret between two or more parties that can be used to maintain a private information link. This requirement that both parties have access to the secret key is one of the main drawbacks of symmetric key encryption, in comparison to public-key encryption.ncrypting a message does not guarantee that this message is not changed while encrypted. Hence often a message authentication code is added to a ciphertext to ensure that changes to the ciphertext will be noted by the receiver. Message authentication codes can be constructed from symmetric ciphers (e.g. CBC-MAC).