Code 55 : AMSCO Cipher

AMSCO Cipher

Principle

The AMSCO cipher uses a transposition method. The matrix is read in line by line. In this process, alternately one or two characters are recorded in a field. For a text like "ANGRIFF UM ACHT UHR"and a key with length five (35124) the following matrix results:

3	5	1	2	4
AN	G	RI	F	FU
M	AC	H	TU	H
R

Now, the matrix is read out column by column. The order of the columns is determined by the increasing values of the key. First, column (1) is read out "RIH", then column (2) "FTU" and so on.
The ciphertext is: "RIHFTUANMRFUHGAC".

Security

The security of the AMSCO cipher depends mainly on the length of the used key that determines the number of possible permutations.