20 May
1993
20 May
'93
3:01 p.m.
I wrote something on this in Cryptologia several years back. I believe it is the April Issue of 1988. It describes how to scramble the tree of the Huffman compression to achieve more cryptographically useful compression. Why is this necessary? Because people often assume that compression removes many of the redundancies of the language. Well, it only does this in a theoretical sense. The patterns are still there. If the Huffman encoding maps "T" to "01", "H" to "1001" and "E" to "11", then the pattern "01100111" is going to be very common in English text, but "10010111" is going to much less common. -Peter Wayner