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Kryha - Marconi Presentation The
Kryha cipher machine is very secure. The most astuce deciphering experts
throughout the world are unable to decipher code prepared with it. Principles The
machine's face showed two concentric alphabets whose letters could be aranged
in any desired sequence. At each depression of a lever on the machine, the
inner alphabet rotated counterclockwise a certain number of steps relative to
the outer alphabet, thereby producing a new plain/cipher alphabetic
correspondence. Each plain text letter was found on one alphabet (useally the
outer one) and the corresponding cipher equivalent lying adjacent to it on the
opposite alphabet ring was written down. Pushing the lever each letter
enciphered shifted the relative position of the two alphabet rings. The
inner disk rotation was controlled by insertion of one of a number of available
"cipher disks". At each depression of the cipher lever, the cipher
disk advanced one sector and drove the inner alphabet forward as many steps as
there teeth in that sector. Set the key 1) Set
the inner and outer alphabets. It is usual to keep the outer alphabets with
letter in alphabet order but use of a mixed alphabet is more secure. 2)
Choose the control disk. Each machine was equiped with the standard disk. It
generates the following shifts: 5 3 2 3 1 2 3 2 4 2 6 1 2 1 3 2 1 Remark:
The machine adds a systematic shift of 4 letters. Then the reals shifts
generated by the standard disk is: 9 7 6 7 5 ... You can
purshase non standard disk of your own design. 3)
Choose the initial position of the inner alphabet and the initial position of
the control disk. Ciphering Before
ciphering a letter, push the lever. Read the plain letter on the outer alphabet
and the cipher letter at the opposite position on the inner alphabet. Remark:
you can agree with your correspondant to cipher a letter and AFTER push the
lever. You can agree to read the plain letter on the inner alphabet too. Deciphering Before
deciphering a letter, push the lever. Read the cipher letter on the inner
alphabet and the plain letter at the opposite position on the outer alphabet. Example Cipher
Text: EGYSO IJUKF PAALW
HLCGP SKQKK PKWUJ NSQCC IUATX FJPUI KHYRW Key: Control
disk: standard disk |