During my last year of PhD, I worked extensively with hashing, particularly in the context of Prefix-Free Parsing (Boucher et al., 2019). This got me interested in the history of these kinds of algorithms. First, I stumbled upon rsync by Tridgell et. al (1996). Next, I began reading about spamsum by Tridgell (2002) and discovered Context Triggered Piecewise Hashing. This is what I will be talking about in this post. You can find a list of references at the bottom of the page.