Dieppe Raid

[vykkagur]

Either way, definitely an interesting theory. A great read is the book "The Secret War", which was based on the BBC series of the same name. Chapters cover not only Enigma and radar, but the Battle of the Beams, Battle of the Atlantic, the air war, V-weapons, the Oslo letter, and a whole raft of miscellaneous topics. I read and re-read this book for years.

[CINDERS]

1st Ed H/C "Green Beach" By James Leasor from my collection for those interested on the inner workings afoot in the Dieppe Raid.

[Surpmil]

The student of cryptography in history will note that capturing the enemy's code books is only of use when he doesn't know you've captured them. Where this was the case in WWI for example, the advantage gained was significant.

If you swarm some locale and seize his code books, the first thing in his after-action report will be, "where are the code books?"



His next step is to change his codes, not merely in detail, but if he is prudent, in a much more sweeping way, for the obvious reason that if the code books are lost then enemy now understands your system from the inside out.

When that kind of change is made, the inevitable result is usually that all your previous work on his codes is more or less nullified and you're back to square one. Of course, once technology allowed the recording of intercepts for future decryption, as in the Venona intercepts, retroactive decryption became possible. But of course retroactive decryption is of limited value in war.

The Ultra Secret was so highly valued and guarded that the very idea of storming ashore to steal an enigma machine or related materials would have been complete insanity. THE LAST thing our side wanted to do was ANYTHING which might make the Germans suspect their system was vulnerable or compromised. That is why great attempts were made to limit the distribution of material, and to disguise its source when it was distributed.

So the idea of a full scale raid like Dieppe as cover for a snatch & grab raid on an enigma facility makes no sense at all to me, unless you're a historian looking for another way to put lipstick on a planning pig called Operation Jubilee.

And after the war the secrecy maintained until Wing Commander Winterbotham's book came out allowed our side to sell used Enigma machines to many second and third world countries and read their mail too for many a year!

(IIRC the credit originally goes to the Polish and French soldiers and agents who secured examples of the machines and moved them from Poland to France, and then to Britain.)

[CINDERS]

Yes they could not let the enemy know exactly how much of their codes had been compromised hence there were a few lambs sent to the slaughter to keep the ruse going.

[vykkagur]

The student of cryptography in history will note that capturing the enemy's code books is only of use when he doesn't know you've captured them. Where this was the case in WWI for example, the advantage gained was significant.

If you swarm some locale and seize his code books, the first thing in his after-action report will be, "where are the code books?"

His next step is to change his codes, not merely in detail, but if he is prudent, in a much more sweeping way, for the obvious reason that if the code books are lost then enemy now understands your system from the inside out.

When that kind of change is made, the inevitable result is usually that all your previous work on his codes is more or less nullified and you're back to square one. Of course, once technology allowed the recording of intercepts for future decryption, as in the Venona intercepts, retroactive decryption became possible. But of course retroactive decryption is of limited value in war.

The Ultra Secret was so highly valued and guarded that the very idea of storming ashore to steal an enigma machine or related materials would have been complete insanity. THE LAST thing our side wanted to do was ANYTHING which might make the Germans suspect their system was vulnerable or compromised. That is why great attempts were made to limit the distribution of material, and to disguise its source when it was distributed.

So the idea of a full scale raid like Dieppe as cover for a snatch & grab raid on an enigma facility makes no sense at all to me, unless you're a historian looking for another way to put lipstick on a planning pig called Operation Jubilee.

And after the war the secrecy maintained under Wing Commander Winterbotham's book came out allowed our side to sell used Enigma machines to many second and third world countries and read their mail too for many a year!

(IIRC the credit originally goes to the Polish and French soldiers and agents who secured examples of the machines and moved them from Poland to France, and then to Britain.)

^^^ What he said.

[Flying10uk]

The student of cryptography in history will note that capturing the enemy's code books is only of use when he doesn't know you've captured them. Where this was the case in WWI for example, the advantage gained was significant.

If you swarm some locale and seize his code books, the first thing in his after-action report will be, "where are the code books?"

His next step is to change his codes, not merely in detail, but if he is prudent, in a much more sweeping way, for the obvious reason that if the code books are lost then enemy now understands your system from the inside out.

When that kind of change is made, the inevitable result is usually that all your previous work on his codes is more or less nullified and you're back to square one. Of course, once technology allowed the recording of intercepts for future decryption, as in the Venona intercepts, retroactive decryption became possible. But of course retroactive decryption is of limited value in war.

The Ultra Secret was so highly valued and guarded that the very idea of storming ashore to steal an enigma machine or related materials would have been complete insanity. THE LAST thing our side wanted to do was ANYTHING which might make the Germans suspect their system was vulnerable or compromised. That is why great attempts were made to limit the distribution of material, and to disguise its source when it was distributed.

So the idea of a full scale raid like Dieppe as cover for a snatch & grab raid on an enigma facility makes no sense at all to me, unless you're a historian looking for another way to put lipstick on a planning pig called Operation Jubilee.

And after the war the secrecy maintained under Wing Commander Winterbotham's book came out allowed our side to sell used Enigma machines to many second and third world countries and read their mail too for many a year!

(IIRC the credit originally goes to the Polish and French soldiers and agents who secured examples of the machines and moved them from Poland to France, and then to Britain.)

The point that you and others have missed is that, at the time of the Dieppe Raid, the allies/Bletchley Park were unable to decode Kriegsmarine Enigma codes because the Kriegsmarine had switched to the 4 rotor Enigma machine. This meant that instead of having the normal 3 rotors, the Kriegsmarine, had started using Enigma machines with 4 rotors and therefore Bletchley Park were unable to read Kriegsmarine messages encoded with the 4 rotor Enigma machine. A 3 rotor Enigma machine can communicate with a 4 rotor Enigma machine if the 4 rotor machine is properly configured so that only 3 of it's 4 rotors are in use, when in communication with a 3 rotor machine. Bletchley Park needed the information on the 4 rotor Enigma machine that was being used by the Kriegsmarine at the time of the Dieppe raid so that it could read Kriegsmarine messages.

The claim has been made that either the main purpose of the Dieppe raid was to steal the Enigma code material, specifically relating to the 4 rotor Enigma machine used by the Kriegsmarine, or that it was decided to "tack" this operation onto the main Dieppe raid.

Either way, I don't see that it is up to me or to anyone else using the Milserps forum, unless they were actually there, to either dismiss or to agree with/confirm the claim.

Personally, I can see the logic in hiding a "pinch raid" within a much bigger raid. As for the Germans noticing the Enigma material "missing", like I say, my understanding is that the intention of the Commandos was to demolish the building, holding the Enigma material, with explosives once the material was removed. I assume that more than one building would have been demolished for obvious reasons.

[Surpmil]

The point that you and others have missed is that, at the time of the Dieppe Raid, the allies/Bletchley Park were unable to decode Kriegsmarine Enigma codes because the Kriegsmarine had switched to the 4 rotor Enigma machine. This meant that instead of having the normal 3 rotors, the Kriegsmarine, had started using Enigma machines with 4 rotors and therefore Bletchley Park were unable to read Kriegsmarine messages encoded with the 4 rotor Enigma machine. A 3 rotor Enigma machine can communicate with a 4 rotor Enigma machine if the 4 rotor machine is properly configured so that only 3 of it's 4 rotors are in use, when in communication with a 3 rotor machine. Bletchley Park needed the information on the 4 rotor Enigma machine that was being used by the Kriegsmarine at the time of the Dieppe raid so that it could read Kriegsmarine messages.

The claim has been made that either the main purpose of the Dieppe raid was to steal the Enigma code material, specifically relating to the 4 rotor Enigma machine used by the Kriegsmarine, or that it was decided to "tack" this operation onto the main Dieppe raid.

Either way, I don't see that it is up to me or to anyone else using the Milserps forum, unless they were actually there, to either dismiss or to agree with/confirm the claim.

Personally, I can see the logic in hiding a "pinch raid" within a much bigger raid. As for the Germans noticing the Enigma material "missing", like I say, my understanding is that the intention of the Commandos was to demolish the building, holding the Enigma material, with explosives once the material was removed. I assume that more than one building would have been demolished for obvious reasons.

Yes, it would have been pretty dicey to to be unable to read the Kriegsmarine's codes for a while, and the greatest danger would have been them noticing that their losses had suddenly gone down dramatically.

As for whether Bletchley & Co could have worked out how a four rotor machine worked, since they had some earlier versions of the three rotor machine, and some very clever people, as well as sense of urgency, I suspect it wouldn't have taken them long, and probably didn't.

Maybe I'm more suspicious than the Abwehr was, LOL, but if I found out that 'one our code machines is missing', and the Allies had stormed the location and blown the place up afterwards, I would have had the surrounding 1000 yards combed on hands and knees for the pieces and if they didn't turn up...well I think the rest is...obvious!

The fact that a larger raid occurred just down the road wouldn't make a pin of difference, anymore than St. Paul's burning down would cover a break in at the Bank of England.

Though it would make a super movie I'm sure.

[Flying10uk]

Yes, it would have been pretty dicey to to be unable to read the Kriegsmarine's codes for a while, and the greatest danger would have been them noticing that their losses had suddenly gone down dramatically.

As for whether Bletchley & Co could have worked out how a four rotor machine worked, since they had some earlier versions of the three rotor machine, and some very clever people, as well as sense of urgency, I suspect it wouldn't have taken them long, and probably didn't.

Maybe I'm more suspicious than the Abwehr was, LOL, but if I found out that 'one our code machines is missing', and the Allies had stormed the location and blown the place up afterwards, I would have had the surrounding 1000 yards combed on hands and knees for the pieces and if they didn't turn up...well I think the rest is...obvious!

The fact that a larger raid occurred just down the road wouldn't make a pin of difference, anymore than St. Paul's burning down would cover a break in at the Bank of England.

Though it would make a super movie I'm sure.

You are entitled to your opinion.

The fact remains that Bletchley Park were unable to decipher coded messages sent by the Kriegsmarine using 4 rotor Enigma machines, over an unexpended period of many months, because they didn't have they necessary means/material to decipher them.

[Surpmil]

You are entitled to your opinion.

The fact remains that Bletchley Park were unable to decipher coded messages sent by the Kriegsmarine using 4 rotor Enigma machines, over an unexpended period of many months, because they didn't have they necessary means/material to decipher them.

Indeed, we are all entitled to logical deduction should we wish to avail ourselves of it.

As for Dieppe, it was a sop to Stalin's angry demands for a Second Front, a way of cooling the Americans' now forgotten, but then burning ardour for charging across the Channel in 1942/3, and an amusing way to bruise up the Canadians who'd been kept sitting around in the UK for years, doing their basic training sometimes as many as three or four times in a row to "keep busy", and whose WWI successes they were emphatically not going to be given the opportunity to repeat in that war, particularly after a series of even more humiliating debacles than those of WWI to which any such successes might then be compared: Dunkirk, Singapore and the Western Desert (Greece and Crete we may leave to the political leadership)

It would be nice to think that the boffins at least could have figured out that beaches comprised of fist-sized stones will not play well with tank tracks, or that seawalls can be significant obstacles to tanks, or that local air superiority is well worth having in combined operations.

But maybe they really did need to "test" all that at the cost of thousand odd lives, I don't know. What do you think?

[vykkagur]

[QUOTE=Surpmil;465373Though it would make a super movie I'm sure.[/QUOTE]

But only if it starred a major American actor (Pitt/Clooney/some fuzzy-faced kid with broody eyes) who enlisted with the Canadians because he couldn't wait to get at 'em. Oh, and there has to be a female. Even in the Sahara, they had to come across a female. 'Cause there always has to be a female character, no matter what. Preferably kick-boxing large numbers of hapless German sentries. (Did anything ever have a shorter life expectancy than the German sentries in 60's WWII movies?)