On the Security of NMAC and Its Variants
Abstract: Based on the three
earlier MAC (Message Authentication Code) construction approaches, we propose
and analyze some variants of NMAC. We propose
some key recovery attacks to
these NMAC variants, for
example, we can recover the
equivalent inner key of
NMAC in
about O(2n/2) MAC operations,
in a related key setting. We
propose NMAC-E, a variant of NMAC with
secret envelop, to
achieve more process
efficiency and no
loss of security, which needs
only one call to the underlying hash function, instead of two invocations in HMAC.
Author: Fanbao Liu, Changxiang
Shen, Tao Xie, Dengguo Feng
Journal Code: jptkomputergg130061
