Klaus Schmeh Aug 21, 2026 Can you decipher this letter sent to U.S. president James Madison? James Madison (1751–1836), the fourth President of the United States, left behind an enormous documentary legacy. Read More 9 comments InUnsolved cryptogram
Klaus Schmeh Aug 14, 2026 The Catokwacopa Cryptograms: A 150-Year-Old Mystery In his book The Agony Column Codes & Ciphers, codebreaker Tony Gaffney presents more than a thousand encrypted newspaper advertisements from Victorian England. Read More 16 comments InUnsolved cryptogram
Klaus Schmeh Aug 5, 2026 An unsolved encrypted document from Reddit A few weeks ago, the following document was shared on Reddit. Read More 8 comments InUnsolved cryptogram