Gears within the M-209 have prime-number ratios to prevent repetitive positions—with over one million positions before the key repeats. The M-209, however, is not fully secure, partly because its prime numbers are short. #MathAtSFO #Mathematics #Math#cryptology#cipherThis tweet was posted on March 28, 2022.
During World War II, all sides used mechanical ciphers. The U.S. military’s M-209 portable crypto machine required users to encrypt text one letter at a time. By turning a crank, the scrambled message printed out on paper tape. #MathAtSFO #Math#cryptology#cipherThis tweet was posted on March 28, 2022.