Cryptography

James Cruickshank Henderson Macbeth, George Fabyan Collection (Library Of Congress) Dlc, Andr B. 1871- Langie, Internet Archive

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• Publié par: anko
• Nombre de lectures: 40
• Langue: English
• Poids de l'ouvrage: 14 Mo

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MurmfflffimffMtmmffflHiB^ v -~* * iCRYPTOGRAPHYCRYPTOGRAPHY BY ANDRE LANGIE TRANSLATED FROM THE FRENCH BY C. H. MACBETHJ. AUTHOR OF "THE MARCONI CODE," "MARCONI ETC.DICTIONARY," CONSTABLE COMPANY LIMITED&7 SYDNEYLONDON BOMBAY 1922PRINTED IN GREAT BRITAINPREFACE I no ofHAVE intention a manual ofwriting complete even is notrelative,cryptography. Finality, very attainable in the domain of this art. Besides, good in on titlesmanuals are existence this and thesubject, of some of them will be found at the end of this volume. A of considerable however,cryptographer experience, can add a few details even to the mostalways complete thisworks of kind. in this book is toMy object writing explainsimply what and to recall what it has beenis,cryptography from to the in to relateshort,antiquity present day; my as aexperiences decipherer. The first of the contains a ofvolume descriptionpart the of with aprincipal systems cryptography, together note on the rule inplayed by cryptography history. inIn the second I relate how I succeededpart decipher- a dozen of various kinds. In someing cryptograms of this section texts as cameI thechapters give just they into but in the ofhands; cases,my majority though the ofpreserving system cryptography actually employed, I on of substituted anhave, grounds expediency, approxi- mate for the actual have theand modifiedtext,reading and even radical features of the in suchnarrative,plan, a as to render abortive at identificationway any attempt and localisation.vi PREFACE aIn the third I some advice inpart give general way on lines which have to me, and, further,proved profitable a certain number of tables and but while Iformulae; shouldthese to be useful, too much reliancerecognise very not be on under of thethem,placed penalty striking as I shall have occasion to farther on.track,wrong repeat In of as I have found infact,point by experience, the are morecryptography exceptions infinitely frequent than the rule. TRANSLATOR'S PREFACE I have to with thanks the valuableacknowledge grateful Iassistance have received in this work frompreparing the late Mr. W. Lieut.-Commander W. W. SmithJarvis, of Mr. AlbertU.S.A., M. Smoot of theWashington, Ledoux New and Miss A. WishartLaboratories, York, of the Radio of America. It was not anCorporation task text for the ofeasy substituting English examples in and if there are errors which haveFrench,ciphers any detection Iinadvertently escaped humbly beg forgiveness. C. H. MACBETH.J.