A capability built into connection- or session-oriented protocols and services. If it is determined that a message, in whole or in part, was corrupted, altered, or lost, a request can be made for the source to resend all or part of the message.

A form of auditing focused on communications. Transmission logging records the details about source, destination, time stamps, identification codes, transmission status, number of packets, size of message, and so on.

The number of packets transmitted before an acknowledge packet is sent.

Based on SSL technology, TLS incorporated many security enhancements and was eventually adopted as a replacement for SSL in most applications. Early versions of TLS supported downgrading communications to SSL v3. 0 when both parties did not support TLS. However, in 2011 TLS v1. 2 dropped this backward compatibility. As with SSL, TLS uses TCP port 443.

Cipher that uses an encryption algorithm to rearrange the letters of a plain-text message to form the cipher-text message.

Product cipher that, like DES, operates on 64bit data blocks. There are several forms, each of which uses the DES cipher 3 times. Some forms use two 56bit keys, some use three. (. See NIST FIPS 463 and CNSSAM IA/0204)

A standard that uses three iterations of DES with two or three different keys to increase the effective key strength to 112 bits.

Hides inside other software. Usually an attachment or download.

Means by which a TOE Security Function (TSF) and a remote trusted IT product can communicate with necessary confidence to support the TOE Security Policy (TSP).

A security development standard for system manufacturers and a basis for comparing and evaluating different computer systems. Also known as the Orange Book.