GNU R package for 'hash digest' of R data structures

 Implementation of a function 'digest()' for the creation of hash
 digests of arbitrary R objects (using the md5, sha-1, sha-256,
 crc32, xxhash and murmurhash algorithms) permitting easy comparison of R
 language objects, as well as a function 'hmac()' to create hash-based
 message authentication code.
 .
 The md5 algorithm by Ron Rivest is specified in RFC 1321, the sha-1
 and sha-256 algorithms are specified in FIPS-180-1 and FIPS-180-2,
 and the crc32 algorithm is described in
 ftp://ftp.rocksoft.com/cliens/rocksoft/papers/crc_v3.txt.
 .
 For md5, sha-1, sha-256 and aes, this package uses small standalone
 implementations that were provided by Christophe Devine. For crc32, code
 from the zlib library is used. For sha-512, an implementation by Aaron
 D. Gifford is used. For xxHash, the implementation by Yann Collet is used.
 For murmurhash, an implementation by Shane Day is used.
 .
 Please note that this package is not meant to be deployed for
 cryptographic purposes for which more comprehensive (and widely
 tested) libraries such as OpenSSL should be used.