Paper 2019/078
Testing the Randomness of Cryptographic Function Mappings
Alan Kaminsky
Abstract
A cryptographic function with a fixed-length output, such as a block cipher, hash function, or message authentication code (MAC), should behave as a random mapping. The mapping's randomness can be evaluated with statistical tests. Statistical test suites typically used to evaluate cryptographic functions, such as the NIST test suite, are not well-suited for testing fixed-output-length cryptographic functions. Also, these test suites employ a frequentist approach, making it difficult to obtain an overall evaluation of the mapping's randomness. This paper describes CryptoStat, a test suite that overcomes the aforementioned deficiencies. CryptoStat is specifically designed to test the mappings of fixed-output-length cryptographic functions, and CryptoStat employs a Bayesian approach that quite naturally yields an overall evaluation of the mappings' randomness. Results of applying CryptoStat to reduced-round and full-round versions of the AES block ciphers and the SHA-1 and SHA-2 hash functions are reported; the results are analyzed to determine the algorithms' randomness margins.
Metadata
- Available format(s)
-
PDF
- Category
- Foundations
- Publication info
- Preprint. MINOR revision.
- Keywords
- Statistical testsBayesian model selectionAES block cipherSHA-1 hash functionSHA-2 hash function
- Contact author(s)
- ark @ cs rit edu
- History
- 2019-01-28: received
- Short URL
- https://ia.cr/2019/078
- License
-
CC BY
BibTeX
@misc{cryptoeprint:2019/078,
author = {Alan Kaminsky},
title = {Testing the Randomness of Cryptographic Function Mappings},
howpublished = {Cryptology {ePrint} Archive, Paper 2019/078},
year = {2019},
url = {https://eprint.iacr.org/2019/078}
}
