Editing 40-bit encryption (section)

{{Short description|Key size for symmetric encryption}}
{{Use mdy dates|date=July 2011}}
'''40-bit encryption''' refers to a (now broken) [[key size]] of forty bits, or five [[byte]]s, for [[symmetric encryption]]; this represents a relatively low [[level of security]]. A forty bit length corresponds to a total of 2<sup>40</sup> possible keys. Although this is a large number in human terms (about a [[1000000000000 (number)|trillion]]), it is possible to break this degree of encryption using a moderate amount of computing power in a [[brute-force attack]], ''i.e.'', trying out each possible key in turn.