ATHBASH (cimmo is a similar term for a some what different principle of commutation. In this, namely, the letters are also mutually interchanged by pairs ; but every pair consists of a letter from each end of the alphabet, in regular succession. Thus, as the technical term Athbash shews, tt and n, and n and v), are interchangeable ; and so on through out the whole series. By writing the Hebrew alphabet twice in two parallel lines, but the second time in an inverse order, the two letters which form every pair will come to stand in a perpendicular line. This system is also remarkable on account of Jerome having so confidently applied it to the word Sheshak, in Jer. xxv. 26. His words are, Quoin odo Babel in telligatur Sesach, non magnopere laborabit qui Hebrxx lingua: parvam saltem habuerit scientiam.' He then propounds the same system of commutation as that called Athbash (without giving it that name however, and without adducing any higher authority for assuming this mode of commutation, than the fact that it was customary to learn the Greek alphabet first straight through, and then, by way of ensuring accurate retention, to repeat it by taking a letter from each end, alternately), and makes ICt, to be the same as 5n,n. (See Rosenmiiller's Scholia, ad loc.)
Hottinger possessed an entire Pentateuch explained on the principle of Athbash (Thesanr. Philol. p. There is also another system of less note, called ALBAM (1:3t.1), which is only a modification of the preceding. For in it the alphabet is divided into halves, and one portion placed over the other in the natural order, and the pairs are formed out of those letters which would then stand in a row together.
All these methods belong to that branch of the Cabbala which is called n-rmn, commutation. J. N.