Abstract:
In 2018 the CTR-ACPKM and OMAC-ACPKM-Master internally rekeyed block cipher modes were adopted in Russian Standardization System and must pass through the last formal standardization stages in IETF. The main distinctive feature of these modes is that during each message processing the key used for data blocks transformation is periodically changed. The security bounds for these modes in the standard IND-CPNA and PRF security models were presented at CTCrypt’18. This paper contains the interpretation of the proposed reductions from the viewpoint of mode resistance to the cryptanalytic methods of various types and the comparative bounds analysis.
Key words:block cipher modes of operation, re-keying, provable security.