Excerpt

[from Chapter 1, Enigma!]:

(April 20, 2000.) Last night, on the Discovery channel, I watched Admiral Gallerys men again capturing the German submarine U-505. My days and nights of turmoil and excitement in 1944 came back to me with a rush. An Enigma cipher machine had been retrieved from that sinking U-boat. What we did with it then at the U.S. Naval Code and Signal Laboratory enabled our forces to locate and sink German submarines! Admiral Dan Gallery told me years later that to capture that Enigma machine was the only reason he allowed his volunteers to board a sinking U-boat.[...]

A week or so after the capture, I was handed an ailing Enigma machine that many men had risked their lives to get. It was heavily damaged by salt water and would not work. Sort of implying that its repair was hopeless, Commander Seiler said, Dick, see what you can do with this thing. What a job! All I had to do was repair an unknown machine whose workings I didnt know, and whose markings were in an unfamiliar language. Yeah sure.[...]



[from Chapter 25, Enigma Betrays its own U-Boats]:

Hurry up dawn, so I can get to the Lab! It is three AM and the amazing answer just woke me! The dreaded day is coming when the U-505 code books expire and there will be no more daily settings for the Enigma wheels. U-boats will again run rampant and kill. What can we do? The answer: make our ersatz Enigma work without code books! Where do these night ideas come from? Who knows? but the deaths at sea of countless soldiers and sailors can be prevented and its up to me to do it.

On my arrival at the Lab, I burst into Commander Seilers office unannounced.[...]Seiler gets the idea right away, and tells me to get going on it right now, after first seeing Lieutenant Skinner, the liaison with Op-20-G, who could get the authorization to destroy another ECM, with its horrible destruction report. It wont be so bad this time, the WAVE in Seilers office having done it before.

Mr. Skinner gasps when I tell him I can run all 26 letters through the maze at once. (Thank God Skinner was an IBM engineer in civilian life.) I would scan the alphabet from A to Z on each operation, and punch the enciphered output in sequence on IBM cards. After accumulating data at different wheel settings, the crypt experts under Captain Safford would be able to break the days cipher without the code books. Skinner would arrange to get the IBM machines and modify them[...], while I would gut and modify the ECM.

Mr. Skinners first objection is a valid one. You cant do it. The Enigma is a reflection cipher, and half the letters going in would meet the other half going out. It is impossible. This problem had baffled me to the point that I had given up on the matter. What hit me last night is that the ECM has two rows of wheels, one for the message, and the other for an unrelated purpose. This row was idle in my first ersatz Enigma, but now it will share the work. My plan is to wire an identical set of wheels for this second row, and route the return through them, thus having a clear 26-line path. Skinner gets the idea and becomes terribly excited. He can hardly wait to get started.[...]

There is no time to lose; the code books have only a few months left. Without a mass of data from the new machine, the cryptanalysts would be back in the dark that existed before the U-505 capture. I decide to work seven days a week for long hours, to rush this project through. Dorothy wonders, but I lie to her and blame orders. It is my wish to work like that, and there are no orders. What we do is not discussed outside, even to ones wife.

What good are a bunch of punch cards? one might ask. This question could be answered by the cryptanalysts. Skinner and I know that with enough data stored on IBM cards, the U-boat messages, after analysis by expert crypt people, will be entered in the IBM machine and zip-zip-zip the cards will come out, and the deciphered text will be printed out faster than even our first machine could. With our new machine, we will be independent of code books!

The machine was built and delivered to Op-20-G via Skinner, never to be seen again by me. A new need to know policy had been set up, and I did not need to know the results. But the grape vine told me that things went as we had forecast. Data were amassed and U-boats sunk in spite of expired code books. The U-boat messages obligingly let us know where the U-boats would be so we could meet them. The book Iron Coffins, by U-boat commander Herbert Werner, poignantly relates how German U-boat sailors were mutinying rather than put to sea. Mutiny by obedient Germans? Unheard of! After the War, it was learned that Hitler asked Admiral Karl von Doenitz, in command of the German submarine fleet, if Enigma had been broken because now U-boats never returned. Impossible! replied von Doenitz. Even our superior mathematicians could never crack that machine![...]

I feel that the making of the two Enigma copies was the most significant action of my life. What I did was vital to all those who would have lost their lives from U-boat attacks during the D-Day build up across the Atlantic. They were saved, but will never know about those of us who saved them or even that they were saved. It gives me a weird feeling to see men of World War II age, and wonder, Were you one of those spared? Or were you? Or you? Or you?