InKey
From Just Solve the File Format Problem
inKey by RA0193 / artem-drobanov / art-drobanov (Drobanov Artem) is a Win32 encryption program for very small (~100K) files.
It uses a very large (>800,000 bit) key and ProcessingTime(data) = O(data2) so is very slow for larger amounts of data
The algorithm is further described in the included inKey.pdf (in Russian)