Book Cipher

Encodes and decodes by positions in a reference text: line and word, line and character, page, line and word (pages split by === or ---), or word number to initial letter, varying the number for a repeated letter. The last is the scheme of The Beale Papers (Lynchburg, 1885), whose cipher no. 2 is keyed to the numbered words of the Declaration of Independence; the Cipher Archive opens it here.

• The Beale Papers (Lynchburg: J. B. Ward, 1885) — Wikisource transcription
• David Kahn, The Codebreakers: The Story of Secret Writing (New York: Macmillan, 1967)