Editing ATM (section)

=== Transactional secrecy and integrity ===

The security of ATM transactions relies mostly on the integrity of the secure [[cryptoprocessor]]: the ATM often uses general commodity components that sometimes are not considered to be "[[trusted system]]s".

Encryption of personal information, required by law in many jurisdictions, is used to prevent fraud. Sensitive data in ATM transactions are usually [[encryption|encrypted]] with [[Data Encryption Standard|DES]], but transaction processors now usually require the use of [[Triple DES]].<ref>[http://www.atmmarketplace.com/research.htm?article_id=25059&pavilion=126&step=story] {{webarchive|url=https://web.archive.org/web/20061012175105/http://www.atmmarketplace.com/research.htm?article_id=25059&pavilion=126&step=story|date=12 October 2006}}</ref>{{update inline|date=March 2023|reason=3DES itself is highly outdated by now.}} Remote Key Loading techniques may be used to ensure the secrecy of the initialisation of the encryption keys in the ATM. [[Message Authentication Code]] (MAC) or [[Partial MAC]] may also be used to ensure messages have not been tampered with while in transit between the ATM and the financial network.