Choose a
hash function H(*, *):{0,1}* x [{0,1}.sup.m] [right arrow] [{0,1}.sup.n].
Hash functions are deliberately designed to be complex, but they also remain consistent so that the same input always produces the same output.
The design requirements of the SAP-NFC protocol can be summarized as follows: (1) all the authentication parties can generate random numbers; (2) the AuC and the NFC devices can renew their secret keys for each authentication session; (3) both the old secret keys of previous authentication session and the new secret keys of the current authentication session of the NFC devices will be saved in the AuC database; (4) the mutual authentication must be conducted between all authentication parties; (5) the new session keys are derived by the KDF functions; (6) the identities of the authentication parties are concealed by a set of
hash functions.
We see, then, that our simple function is a valid
hash function, just not a very good one: It behaves with perfect consistency but produces many collisions.
The
hash function Keccak was utilized to assess the impact of generic
hash functions on constrained environments.
The main input to the
hash function is the message block input and the main output is the digest (or hash value).
* In order to exchange message, each user has to compute two scalar multiplications, exponentiation,
hash function and summation.
Here, R denotes the random variable identifying the
hash function. When a random
hash function [f.sub.R] is linear, it is [delta]-almost [universal.sub.2] if and only if
becomes a
hash function that maps the integers between 1 and 12, the
Section 4 designs a kind of lightweight RFID authentication protocol based on
Hash function from the vertical aspect.
About authentication before transmission, some schemes, for example, Hwang and Yeh's [11] two-way authentication scheme between nodes, Peyravian and Jeffries's [12] authentication scheme based on
Hash function, Wang et al.'s [13] two-way anonymous password authentication scheme, and Kothmayr et al.'s [28] endto-end two-way authentication mechanism for IoT based on DTLS protocol using the existing public key encryption algorithm, have been proposed.
The
hash function in data-independent methods is typically randomly generated and is independent of any training data.