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REF ID:A66oJ'E/;y~r.J!,J ~ tJ'~~-

• TOP SECRET • ~:s:-~ With the agenda before us, it won't take much time to review briefly 

the ground to be covered in the technical sessions of this Conference. 

It is h.a.rd1y necessal"T to say that AFSA has many problems of 

current interest and that these are all of importance. It it ~re possible, 

I 1m sure we would find it useful if at this first Conference SC.AG could 

look into several of these problems. But we know that evel"T member who 

has consented to serve on SCAG is a veey bus;r man, and can de~te onl.7 a 

quite limited amount of time to a consideration or AFSA's problems. 

Hence, it is advisable that we present at this first_ Conference onl.7 one 

ot AFSA's problems, and for this reason have selected not only the .m.ost 

urgent one but also the one to the study of which the members of SCAG, by 

virtue of their special exper11111ce and capabilities, can bring lmowledge 

to bear and suggest techniques which JD&7 be conducive to its early 

solution. 

'!he technical sessions will therefore be confined strictl.T to the 

presentations required to develop the ~chnical background SC.AG will need 

in order to understam the nature or that problem, and .in broad outline to 

present the dir~ctions in which our past experience with similar problems 

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-Declassified and approved for release by NSA on 04-02-2014 pursuantto E.O. 1352a - --
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indicates the research should travel. The specific problem is one which 

involves a cipher machine of apparently quite complex construction. I 

say "apparently quite complex construction" because not only have we never 

seen the machine but also we have been unable to gather by covert intelligence any information whatever concerning its construction. What little we 

A 

lalow about it has been derived by deductive and inductive re~soning, based 

upon our studies of the cryptograms produced by.~he machine and collected 

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for us by our intercept stations. 

, 

. However, our inability to gather by direct or covert operations the 

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~ ... - . -- technical details as to the construction of the machine need not constitute 

a frustrating bar to success in its solution. We have a good precedent for 

this statement, from our experience back in the two or three years preceding 

the attack on Pearl Harbor, during which period we were able to solve and 

reconstruct the complex cipher ma.chine used by the Japanese Foreign Office 

and a similar machine used by the Japanese Navy for their highest echelon 

secret radiocommunications. We not only did this without preliminary 

knm~ledge of these machines but also we built analogs which were better than 

the Japanese machines themselves, as we learned after VJ-Day, when at last 

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e REF ID:A66055e 

-lQP SECRETwe were able to pick up one of the Japanese Navy ma.chines intact. We 

never did pick up one of the Japanese Foreign Office machines intact - we 

found a badly damaged one in the ruins of the Japanese Embassy in Berlin, 

in 1945. 

Turning now to the agenda for the first technical session, LCDR 

Gleason is going to tell you immediately after lunch something about the 

way in which a complex problem was successfully handled in World War II. 

That problem also involved a cipher machine, one of German origin, used 

by all the German Armed Forces, and although we knew practically all the 

major 

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details of its construction and method of operation, the problem 

was one of great difficulty. Not wishing to intrude on Commander Gleason's 

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preserve I won't say more about his presentation except to indicate that 

it is principa+ly intended to provide general background as to cryptanalytic techniques in actual practice, as against purely theoretical 

approaches or methods. 

Following his presentation there will be a tour at this station to 

take a look at several analytic or cryptanalytic machines, designed to meet 

general ar specific specific~ons dictated by- the nature 

anal;yt:ic probl.ema, to "h:ich'8iJ,h~T•••d. 

of the crypt-
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.• 

~ . . 

The technical session and tour this at:ternoon are intended to serve 

1. 

as immediate background for tP,e specific probl~··we think you can aa'a"'ist 

in solving; and tomorrow morning we shall begin on the problem itself. 

At the end of each presentation or tour there will be opportunity to 

ask questions. These we welcome and, in view of what Admiral Stone has 

said regarding the security bars having been let down so far as SCAG is 

concerned, I hope that the informality of our meetings will be conducive 

to your feeling utmost freedom to ask any questions you deem pertinent. 

We will answer them to the very best of our ability. There is, however, 

one point in this connection that I must mention. Admiral Stone has 

indicated why •ve have found it essential to apply a rather strict com.partmentation upon the activities, operations, and results obtained in certain 

areas of AFSA's work. It will be perfectly permissible to ask questions 

when we are assembled in a conference room; but when we are making the _ 

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tours of actual installations it will be necessary that you reserve your 

questions until we reassemble in a conference room, because, strang~ as it 

may appear, many of the people who actually operate some of our .nia.chines 

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do not know the details of the problem in connection with which the 

machines are being em.ployed. 

Tomorrow afternoon there will be further presentations directly 

involving the specific problem. At that time will be a good opportunity 

to make a tour of machines at our other cryptanalytic center, the one at 

Arlington Hall Station, across the Potomac. After that tour, there will 

be a discussion period on one subject, and then SCAG will be divided into ._ 

two sub-groups, one consisting of those who are especially interested in 

the mathematical aspects of the problem, the other, of those who are 

~specially interested in the electronic components of the analytic 

machines which we think may help us reach the solution to the problem. 

The final session 1rdll be at Arlington Hall station and will be 

devoted to discussing, in a preliminary way, the paths along which, having 

learned of our various approaches, you think our research might be directed. 

We feel sure that you will be able, if not at this time then after you have 

thought the matter ov~r, to make valuable suggestions toward the solution 

of our most pressing problem. Its urgency is one that claims all our best 

efforts. TOP SECRET ...