For example, SHA-256 operates on 512-bit blocks. The size of the output of HMAC is the same as that of the underlying hash function (e.g., 256 and 1600 bits in the case of SHA-256 and SHA-3, respectively), although it can be truncated if desired. HMAC does not encrypt the message.

2013-9-3 SHA-3 Standard: Permutation-Based Hash and Extendable 2015-8-4 · : SHA-3 Standard: Permutation-Based Hash and Extendable-Output Functions (FIPS PUB 202). 2. Category of Standard: Computer Security Standard, Cryptography. 3. Explanation: This Standard (FIPS 202) specifies the Secure Hash Algorithm-3 (SHA-3) family of functions on binary data. Each of the SHA-3 functions is based on an instance of the K MD5、SHA-1、HMAC、HMAC-MD5和HMAC … 2002-12-30

## To summarize, we believe that SHA-3 must exhibit great performance on as wide a range of commodity processors as possible, and should exploit the current Moore’s law trend towards parallelism. A very large number of applications use HMAC-SHA1 or HMAC-SHA256 for authenticating relatively short messages.

The slave accessory then inputs its unique ID, unique secret, and the challenge into its SHA-3 engine to compute a SHA-3 HMAC. This HMAC is returned to the host. During the process of this RFC 4634 SHAs and HMAC-SHAs July 2006 If Z is an integer, 0 <= z < 2^64, then z = (2^32)x + y where 0 <= x < 2^32 and 0 <= y < 2^32. Since x and y can be represented as words X and Y, respectively, z can be represented as the pair of words (X,Y). : SHA-3 Standard: Permutation-Based Hash and Extendable-Output Functions (FIPS PUB 202). 2. Category of Standard: Computer Security Standard, Cryptography. 3. Explanation: This Standard (FIPS 202) specifies the Secure Hash Algorithm-3 (SHA-3) family of functions on binary data. Each of the SHA-3 functions is based on an instance of the K

### 关于密码学：根据RFC2202在Java中HMAC-SHA1 …

Unfortunately SHA-3 is not of the same type. And cannot be directly plugged in to HMAC, to give an instantiation of the hash-and-MAC approach. And, for that reason different mechanisms for achieving message authentication based on SHA-3 are currently being worked out. The SHA-3 symmetric-key algorithm preserves integrity. This is generated by feeding the message and key to the SHA-3 engine. The resultant HMAC and message is then sent to the recipient. Provides a Racket interface to the OpenSSL implementation of SHA-1 and SHA-2. SHA-2 includes four flavors: SHA-224, SHA-256, SHA-384, and SHA-512. Hashing is based on a one-way mathematical function; functions that are easy to compute, but significantly tough to reverse. Hash functions are the basis of the protection mechanism of Hashed Message Authentication Codes (HMAC). It is a major enabling technology for network security used to achieve specific security objectives. For the four SHA-3 candidates where the digest length is fixed, the input block length is assumed to be the bitrate r and the output length is the digest length of the candidate. where the bitrate is the permutation size (1600 bits / 200 bytes) - capacity (2x digest size for SHA-3 / Keccak).