Portax Tutorial


The Portax cipher is a periodic, digraph based cipher similar to the Slidefair. Like the Slidefair, it is based on one of the classic periodic ciphers (The Porta in place of the Vigenère, Variant or Beaufort used by Slidefair). The major difference between the two ciphers is the method of choosing the digraphs the cipher is applied too. In Slidefair the digraphs are taken sequentially from the plain text. In Portax, the plain text is laid out in pairs of rows of period length and the the digraphs are formed from the vertical columns. Continue reading Portax Tutorial