Like the
ATBaSH cipher the ALBaM
cipher is another way of
permuting the
Hebrew alphabet. It's rule is as follows: As the name implies
Aleph becomes
Lamed,
Beth becomes
Mem. Basically, Each of the twenty-two
letters is shifted by eleven places.
Programmatically or
mathematically this could be represented as: f(x) = (x + 11) % 22 (note that % represents the
modulus operator)
Both ATBaSH and ALBaM are interesting in that they are unique cases within a larger system of less notable permutations. (Permutation Meditation will hopefully discuss these and others like them in much more detail.) While ATBaSH makes the end the beginning, and the beginning the end, ALBaM turns the alphabet inside out, making the middle the outside and the outside the middle.
English might similarly be permuted in this way by shifting each letter thirteen places. This is because English has twenty-six letters. (This would be f(x) = (x+13)%26)
The generalised formula for this cipher with any letter x of any alphabet of length n would be: f(x,n) = (x + (n / 2)) % n