IAPM (mode) explained

Integrity-aware parallelizable mode (IAPM) is a mode of operation for cryptographic block ciphers. As its name implies, it allows for a parallel mode of operation for higher throughput.

Encryption and authentication

At the time of its creation, IAPM was one of the first cipher modes to provide both authentication and privacy in a single pass.^{[1] [2] [3]} (In earlier authenticated encryption designs, two passes would be required to: one to encrypt, and the second to compute a MAC.)

IAPM was proposed for use in IPsec.^[4]

Other AEAD schemes also provide all of the single pass, privacy and authentication properties. IAPM has mostly been supplanted by Galois/counter mode.

See also

• OCB mode

Notes and References

1. Jutla . Charanjit S. . Encryption Modes with Almost Free Message Integrity . 1 August 2000 . PS . April 2, 2010 . . ACR Report 2000/039.
2. Jutla . Charanjit S. . Encryption Modes with Almost Free Message Integrity . EUROCRYPT 2001 . https://www.iacr.org/archive/eurocrypt2001/eurocrypt-2001.html . 6 May 2001 . 521 .
3. Web site: OCB: Background (What did Jutla do?) .
4. Web site: A Parallelizable Authenticated Encryption Algorithm for IPsec . C. S. . Jutla . IETF . November 2000 . 2018-01-30.