System, terminal og fremgangsmåte for å oppgradere terminaler for å opprettholde sikkerheten ved kommunikasjonsnettverk

摘要

A secure communication network serves a plurality of terminals (30, 34, 38) grouped into different security categories. Each terminal includes a replaceable security element (32, 36, 40) containing a security algorithm specific to the security category to which the terminal is assigned. Upon the breach of a particular security version, the security elements in the affected category are replaced with new elements containing a different algorithm. The security elements are relatively low cost, and can be replaced on an as needed or periodic basis to maintain system security.