'''Multiple encryption''' is the process of [[encryption|encrypting]] an already encrypted message one or more times, either using the same or a different algorithm. It is also known as '''cascade encryption''', '''cascade ciphering''', '''multiple encryption''', and '''superencipherment'''. '''Superencryption''' refers to the outer-level encryption of a multiple encryption.
Some cryptographers, like Matthew Green of JohnsJohn Hopkins University, say multiple encryption addresses a problem that mostly doesn’t exist: ''Modern ciphers rarely get broken... You’re far more likely to get hit by malware or an implementation bug than you are to suffer a catastrophic attack on [[Advanced_Encryption_Standard|AES]]''.<ref>{{cite web |last=Green |first=Matthew |title=Multiple Encryption |url=https://blog.cryptographyengineering.com/2012/02/02/multiple-encryption/ |date=February 2, 2012}}</ref> .... and in that quote lies the reason for multiple encryption, namely poor implementation. Using two different cryptomodules and keying processes from two different vendors requires both vendors' wares to be compromised for security to fail.
