A new version of the digest package (which generates hash function summaries for arbitrary (and possibly nested) R objects using any of the standard md5, sha-1, sha-256 or crc32 algorithms) is now on CRAN.
Murray Stokely noticed a corner case where a file that was inaccessible lead to a segmentation fault. Thanks to his patch, this is now caught and flagged. He even added a test for it and fixed another one of my idioms. Nice work, so keep the patches coming folks 🙂