<P> Modern ATM physical security, per other modern money - handling security, concentrates on denying the use of the money inside the machine to a thief, by using different types of Intelligent Banknote Neutralisation Systems . </P> <P> A common method is to simply rob the staff filling the machine with money . To avoid this, the schedule for filling them is kept secret, varying and random . The money is often kept in cassettes, which will dye the money if incorrectly opened . </P> <P> 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 systems". </P> <P> Encryption of personal information, required by law in many jurisdictions, is used to prevent fraud . Sensitive data in ATM transactions are usually encrypted with DES, but transaction processors now usually require the use of Triple DES . 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 . </P>

An automated teller machine (atm) is an example of a ____