cryptography Cryptography, or cryptology (from "hidden, secret"; and ''graphein'', "to write", or ''-logy, -logia'', "study", respectively), is the practice and study of techniques for secure communication in the presence of Adversary (cryptography), ...

, CWC Mode (Carter–Wegman + CTR mode) is an AEAD block cipher mode of operation that provides both encryption and built-in message integrity, similar to CCM and OCB modes. It combines the use of CTR mode with a 128-bit block cipher for encryption with an efficient polynomial Carter–Wegman MAC with a tag length of at most 128 bits and is designed by Tadayoshi Kohno, John Viega and Doug Whiting. CWC mode was submitted to

NIST The National Institute of Standards and Technology (NIST) is an agency of the United States Department of Commerce whose mission is to promote American innovation and industrial competitiveness. NIST's activities are organized into physical s ...

for standardization, but NIST opted for the similar GCM mode instead. Although GCM has weaknesses compared to CWC, the GCM authors successfully argued for GCM. CWC allows the payload and associated data to be at most 2³² - 1 blocks or nearly 550 GB.

References

External links

CWC mode home page

CWC: A high-performance conventional authenticated encryption mode
on Cryptology ePrint
Implementation of CWC
on top of AES. Block cipher modes of operation Authenticated-encryption schemes {{crypto-stub