Simple Cypher is compatible with Snow Leopard (10.6) and higher.
Simple Cypher is a computer version of a cypher system developed by Thomas Jefferson. The original system used numbered, wooden wheels and a spindle with two end caps. Each wheel had all 26 letters around the edge in random order. The Sender noted the order in which wheels were placed on the spindle. Then, each wheel was rotated as necessary to spell out the message. Finally, the caps were pressed tight so that all wheels rotated together and the spindle was rotated to any other row which became the encyphered message. The wheel order and the encyphered message were sent to the Receiver (separate messages) who reversed the steps to recover the plain text message. Simple Cypher is $10 shareware. The User may try Simple Cypher in Demo Mode for five launches before registration is required.
Above is similar to what you see when you launch Simple Cypher. The list on the left is the list of numbered wheels (top number is the wheel on the left; bottom number is the wheel on the right), and the wheel number is shown in the small fields at the top. The second row of fields are the letters displayed for each wheel. In the above screenshot, wheel 16 is on the left and letter I is displayed on that wheel. The list of wheel numbers (separated by dashes) is displayed in the Green field. The row of letters displayed is shown in the Red field. The Blue up/down control at the right rotates the wheels together. The "Scramble" button scrambles the wheel order. The "Solve" button rotates each wheel as necessary to make the wheels match the letters in the Yellow field.
Above you see that the Sender has entered a clear text message "attackatdawn". This message is fewer than 24 letters; random letters will be added to make a total of 24 letters. The message may be entered in upper or lower case letters.
Above you see that the Sender has clicked on the "Scramble" button and the wheels have been reordered randomly. Alternatively, the Sender can drag reorder the wheels in any order.
Above you see that the Sender has clicked on the "Solve" button. The message has been made upper case and additional random letters have been added to make 24 letters total. Each wheel has been rotated separately to match the message letter. "Match" is now displayed in red to indicate that the Red field now matches the Yellow field.
Above you see that the Sender has used the Blue up/down control to choose another row, which is displayed in the Red field. This row will be the encyphered message. The Sender then sends the Wheel Sequence in the Green field to the Receiver so that he can assemble his wheels in the same order. The Sender sends the encyphered message in the Red field to the Receiver in a separate message.
Above you see the initial display at the Receiver end (note that the wheels come up in random order so what you see will be different but similar).
Above you see the Receiver has pasted the encyphered message into the Yellow field.
Above you see that the Receiver has dragged the wheel numbers in the table on the left to be the same as the order used by the Sender.
Above you see the Receiver has clicked on the "Solve" button and the wheels have been rotated separately to match the letters in the Yellow field. "Match" is displayed when the Red and Yellow fields are identical.
Finally, you can see above that the Receiver has used the Blue up/down control to rotate the wheels to find a clear text message in the Red field.
Click here to download Version 2.2.1 (2.0 MB) for Macintosh (OS 10.6 or later).