About
This site is a private notebook. There is no analytics tracker, no
newsletter, no comments form. If you find a mistake, or an interesting paper
that fills a gap in one of these notes, please send an email to notes
[at] wlipton.wisderfin.ru; I read incoming mail roughly once a week.
I try to keep entries short. Each one targets a single observation — a theorem, an attack, a piece of design rationale — and traces it from the historical motivation to a self-contained restatement. A new entry appears maybe once or twice a month; the cadence is slow on purpose, because most of the writing time is spent on the parts you don't see: working through the exercises in the relevant chapter of Katz–Lindell, Schneier, or whichever textbook is the canonical reference.
The choice of topics drifts. There is a thematic core around modern cryptography — block ciphers, hash functions, public-key constructions — but information-theoretic results, like Shannon's source coding theorem, show up when they feel relevant. So do occasional notes on the history of a particular construction, when the historical accident matters for understanding why we have the construction in the form we do.
I am not a research cryptographer. Treat the notes as study material written by a careful amateur. Where the underlying material is contested or where I have a personal interpretation, I try to flag it. Where the material is settled, I follow the textbook treatment.