barrettotte / fortran77-enigma

Enigma machine emulator in Fortran77 (fixed-format)

Fortran77-Enigma

Enigma machine emulator in Fortran77. With this project I tried to abide by the rules of Fortran77 the best that I could. Such as column number limit and variable naming up to 6 characters.

Notes

• Intrinsic Functions used: LEN, MOD
• Compiled on Ubuntu usinng gfortran compiler with default flags.
• Input is read from file named @INPUT
• Encryption is output to file named @OUTPUT
• The code doesn't look great, but Im not going to fix it. This is just a small weekend project.

Limitations

• User is expected to correctly populate plugboard (no duplicate keys).
• The max file size has not been tested, but its probably pretty small.

Diagram of Enigma Machine

From http://enigma.louisedade.co.uk/howitworks.html

Sources Used

• Enigma emulator with mechanics explanation http://enigma.louisedade.co.uk/howitworks.html
• Details of enigma machine rotors https://en.wikipedia.org/wiki/Enigma_rotor_details
• Detailed information on engima machine https://en.wikipedia.org/wiki/Enigma_machine
• Oracle docs on Fortran77 https://docs.oracle.com/cd/E19957-01/805-4939/index.html
• Old Fortran77 book that was an amazing reference amazon