John Eglington Bailey

“ The deciphering of them is one of the most difficult of tasks. A method of this kind is explained in the Latin and English lives of Dr John Barwick, whose correspondence with Hyde, afterwards earl of Clarendon, was carried on in cryptography. In a letter dated 20th February 1659/60, Hyde, alluding to the skill of his political opponents in deciphering, says that “nobody needs to fear them, if they write carefully in good cyphers.” In his next he allays his correspondent’s apprehensiveness as to the deciphering of their letters. ”

“ To this kind of cipher-writing Buxtorf gives the name Athbash (from a the first letter of the Hebrew alphabet, and th the last; b the second from the beginning, and h the second from the end) . Another Jewish cabalism of like nature was called Albam; of which an example is in Isaiah vii. 6, where Tabeal is written for Remaliah. In its adaptation to English this method of transposition, of which there are many modifications, is comparatively easy to decipher. A rough key may be derived from an examination of the respective quantities of letters in a type-founder’s bill, or a printer’s “case.” ”

“ Philip Thicknesse (A Treatise on the Art of Decyphering and of Writing in Cypher) , 1772; William Blair (the writer of the comprehensive article “Cipher” in Rees’s Cyclopaedia) , 1819; and G. von Marten (Cours diplomatique) , 1801 (a fourth edition of which appeared in 1851) . Perhaps the best modern work on this subject is the Kryptographik of J. L. Klüber (Tübingen, 1809) , who was drawn into the investigation by inclination and official circumstances. In this work the different methods of cryptography are classified. ”