So as an belated into, digest provides hash digests of arbitrary R objects by relying on the wonderss of
R's serialize() function, and a simple interface to (C-level)
md5, sha-1 and crc32 functions. Clearly, digest is not meant for
crypto but rather to quickly summarize, compare or even cache complex R
objects that may have arisen from larger computations or
simulations. Apparently, Henrik uses digest to compute hash
functions of arbitrary R objects that can be cached using his R.cache package.