100 Mr. Chenevix on a new Method 



trial is proposed as an extreme case ; for, as in practice, the dif- 

 ficulty between using two keys or one is very trifling, and the 

 security at least one hundred times as great in the former case ; 

 it would always be more advantageous that two should be used. 

 The trial here made is under the same circumstances as would 

 attend the cipher in practice. No known sentence is given as a 

 help to detection. 



Cipher No. 18. 

 sxkepazb ^s^ S^vfms kq IswmhpjSoedn vcka iihpjzh d>rss rv 

 yamp bzimdyk xcjw berr vxv z4qbm lyterj rv faro y84aekay 

 a^vh (ifaSg^i au bupcyr ddiaxcjw ^ykShmx pp yt<p4hpold yjy if 

 h4vfb ^kxdpz vvz gf 8a r4up4j pip jjmw uuut4 wuvipgzblych 

 qxkzpfFaqjq liy <phpxt trdt etev dSfq ceyucxegS pici pici xs. 



Upon the whole the advantages of this cipher are, 1st, its 

 extreme simplicity in every respect, for any person may make 

 himself complete master of it in ten minutes : 2nd, the symbols 

 used are familiar to all persons, and easily written and read : 3rd, 

 but one symbol is used to express each letter, hence there is no 

 greater danger of committing errors than in copying any other 

 unknown language, and no more time lost than in any other 

 work of substitution : 4th, it is as secret as a cipher can be, for 

 its power exceeds the limit (m — 1)": 5th, it is applicable to 

 every language : 6th, it is applicable to every system of signals 

 by sea and land, and to every species of secret correspondence 

 by telegraphs, flags, Sfc, where letter symbols or signals are 

 used, as these alone are susceptible of being reduced to fixed 

 and general principles : 7th, any number of ciphers may be dis- 

 tributed and employed without danger of detection, as it is im- 

 possible for any person to decipher a sentence, unless he is in 

 possession of the exact keys, by means of which it was ciphered; 

 and no one diplomatic agent could penetrate the secrets of ano- 

 ther, while the chief alone may be possessed of all. 



To ascertain the degree of secrecy which this mode of cipher- 

 ing really possesses, it is here submitted to inspection, and to 

 very severe trials. It is not presumed that any person will be 

 able to decipher the above unknown sentences, even those which 



