HTTP Developer’s Handbook

Cache Digest Protocol

Cache Digest Protocol is a caching protocol that utilizes digests to help eliminate the necessity of peer queries. A digest is a compressed summary of a cache’s contents, and a cache keeps a digest for each of its peers. Users of mailing lists are probably familiar with the digest mode available in most mailing lists. This option allows the subscriber to receive a single message per day with all of the day’s messages rather than receive each message. A cache digest is similar in that it summarizes a specific cache’s contents, but the format is compressed at the risk of not having perfectly accurate information in the digest. Much like a failed query using ICP, a failed lookup in a digest only makes an accurate response ...