Allied Code Breakers Compromised

What would be some consequences of the Axis powers learning that their codes have been compromised by Allied code breakers early in the war?
How would this scenario likely occur?

I am aware many have pointed out in previous threads that Axis intelligence efforts weren't as effective as some of their Allied counterparts.

I've posed this question once before on yahoo questions, but want to see what everyone here thought.

I don't see it changing the outcome of the war. It might delay it by a few months.
 
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Rubicon

Banned
Thing is that the allied code breakers only gleaned fragmentary glimpses of the German messages early in the war, it wasn't until after the seizure of an enigma and it's code keys from Julius Lemp's U-110 on May 9th 1941that Bletchley Park could really break particularly the Naval Enigma currently and fluently. Though to be fair Bletchley Park had broken the Luftwaffe Enigma earlier and never lost that code either.

Effects: early on, nothing really changes.

1941-43 greater losses of merchants in convoys as it will be harder to divert convoys around U-boats. No sinking of the Milchküh resupply subs either. More merchant shipping lost in the Americas from -42 and onwards.

Less interceptions of the axis convoys in the Med to Panzerarmée Afrika, harder fight for the 8th Army.

The real deal breaker comes in the Pacific. Without breaking any of the Japanese codes that fight will become much more confusing for the Allies, I have no doubt that the Western Allies will win, but they will take more casualties and it would probably take longer to do so.
 
It makes a limited amount of difference, the British already own the German spy networks, so they'll know about any new happenings almost as soon as most of the Germans themselves will, and the Americans will probably have little trouble cracking the Japanese codes again, even if they change them. Also, the losses to shipping will be limited more by radio-direction-finding than by code-breaking,since you only need to know the direction an un-cracked code is coming from to find its source, not so great on land, due to phone lines, but at sea...
 
What is a realistic scenario where the Axis discover the allies have breached their most sensitive secrets?

I think the consequences would generate many butterflies, but not enough to change the outcome.

And there would be consequences. Any nation would try to figure out how and why their secrets aren't so secret. I'd expect code changes, but also plenty of arrests and purges.
 

Cook

Banned
I don't see it changing the outcome of the war. It might delay it by a few months.
Had Erich Raeder realised that the Kriegsmarine’s codes had been compromised during the Battle of the Atlantic in 194041, the outcome of the war might very well have been different.
 

iddt3

Donor
Had Erich Raeder realised that the Kriegsmarine’s codes had been compromised during the Battle of the Atlantic in 194041, the outcome of the war might very well have been different.

Indeed. The RAF might have been forced to devote serious numbers of aircraft to Coastal Command, rather then harassment raids against Germany.
 
There were leaks of this IOTL early in WWII. The Axis just dismissed the mere thought that the inferior subhuman allies could read their codes and flipped to the next section of the paper.
 
The Germans didn't consider the French and British to be subhuman, just decadent and corrupt.

As for finding out the codes are broken: they'd switch to a new code, which Bletchley Park would almost certainly break too, being at the forefront of computer technology at that point. Gives a dicey few months, though.

And for examples of what the Germans could do when they had accurate information on Allied movements (look up Bonner Fellers), see the North African campaign.
 
The question is though, what do the Germans do if they find out Enigma has been cracked?

Can you just drop more rotors onto an Enigma machine? I'd guess not, probably more to it than that. Do the Germans even keep faith in mechanical coding or do they switch to code books?
 
I wonder if the Germans had found out at that point that all of their WWI code-books were compromised early on in the war...
 
What is a realistic scenario where the Axis discover the allies have breached their most sensitive secrets?

I think the consequences would generate many butterflies, but not enough to change the outcome.

And there would be consequences. Any nation would try to figure out how and why their secrets aren't so secret. I'd expect code changes, but also plenty of arrests and purges.


otl possible moments figuring out that enigma was compromised:

1. capture of one general or another who spills the beans or has compromising documents around

2. the germans read deeper into their success in the channel dash; something along the lines of hey, we kept this pretty secret and only communicated on the local phone network and caught the british totally flat footed I wonder if we should try that again

3. reading deeper (a la above) when rommel advanced against enigma orders such as the first cyranaica offensive or the rebound from crusader and caught the british flat footed

4. rommel not dashing to the wire after whipping the 8th army at sidi rezegh during operation crusader and instead massing both panzer divisions and the xx italian corps to encircle and finish off the british xxx corps; if their war diary was captured (forgetting over informed people) a strong investigation of it would show that german mail was being read


major pod but plausible way for the germans to find out

something akin to my operation full moon in manstein in africa; namely a parallel german and italian operation; where the german component gets crushed by prepositioned forces and the italians have a cake walk

italian military codes were unbreakable (they used one time cipher pads of the sort that were very popular with the kgb in the 70's and 80's... tom clancy's red rabbit has an excellent description of how they work)... the british couldn't read italian military signals until the germans forced them to switch to enigma in 1942 :rolleyes:

so some sort of investigation of a battle like full moon would find the difference in signal equipment as a possible reason for the disproportionate results
 

Daffy Duck

Banned
Comment

No doubt the Germans would try to lure the Allies into a trap by feeding false or misleading information to them. They would try to string the Allies along as long as they could...
 
No doubt the Germans would try to lure the Allies into a trap by feeding false or misleading information to them. They would try to string the Allies along as long as they could...

i agree; the germans gets 1 or 2 opportunities to lay a suckerpunch of some proportions on the allies if they find out and can keep it to themselves

something like ordering a "big convoy" to sail to tripoli; but in fact the ships are war ships covered by large numbers of aircraft looking to ambush the rn who are only expecting lightly escorted merchies
 
i agree; the germans gets 1 or 2 opportunities to lay a suckerpunch of some proportions on the allies if they find out and can keep it to themselves

something like ordering a "big convoy" to sail to tripoli; but in fact the ships are war ships covered by large numbers of aircraft looking to ambush the rn who are only expecting lightly escorted merchies

On the other hand the Soviets had very little equivalent to Enigma earlier on in the war, relied on it far less than the Allies did, and won their victory through more old-fashioned signals intelligence than the newfangled versions used by the Allies. On the other other hand the Soviets were the ones fighting a more or less traditional land war of maneuver and sweeping advances and retreats, it was the democracies who fought the kind of war where intelligence has influence all out of proportion to the other elements needed to engage in successful warfighting.....
 
Realistically though even if the Germans/Japanese figure tings out the Allies will, to a lesser degree, re-break them. Plus, the Soviets have anenormous spy network in Nazi Germany getting constant information about economic and military matters, even down to OOBs and operational plans.
 
I'm reading a book on the Allied invasion of North Africa right now, and it mentioned that, in a terrible risk, one of the officers sent to negotiate the surrender of the Vichy forces in North Africa was privy to the fact the Allies were reading ULTRA. If he had been captured and turned over to the Gestapo, he could have revealed it.
 
On the other hand the Soviets had very little equivalent to Enigma earlier on in the war, relied on it far less than the Allies did, and won their victory through more old-fashioned signals intelligence than the newfangled versions used by the Allies. On the other other hand the Soviets were the ones fighting a more or less traditional land war of maneuver and sweeping advances and retreats, it was the democracies who fought the kind of war where intelligence has influence all out of proportion to the other elements needed to engage in successful warfighting.....

Agreed on how the soviets got their business done

however, let's say the Germans figure out enigma is compromised by deduction (say from putting 2 and 2 together on the channel dash and some of Rommel's against orders attacks)... they won't know how or why it got compromised, just that it happened

would they assume the british built a brilliant first generation computer and were using that with some captured material to break codes; or would they blame spies or assume they had a combination of leaks and penetrations?

one would have to assume that if they figured that out, that at minimum the Gestapo would run a series of sweeps and very carefully examine (torture) a large number of people; which would likely find and eliminate a number of key soviet assets

they could never possibly sweep them all, but the soviet intel apparatus would likely suffer collateral damage if the germans go on a paranoia binge
 
Realistically though even if the Germans/Japanese figure tings out the Allies will, to a lesser degree, re-break them. Plus, the Soviets have anenormous spy network in Nazi Germany getting constant information about economic and military matters, even down to OOBs and operational plans.

it would depend on what the germans switched to; the italian system (as later used by the kgb) was unbreakable even with 80's technology
 
Agreed on how the soviets got their business done

however, let's say the Germans figure out enigma is compromised by deduction (say from putting 2 and 2 together on the channel dash and some of Rommel's against orders attacks)... they won't know how or why it got compromised, just that it happened

would they assume the british built a brilliant first generation computer and were using that with some captured material to break codes; or would they blame spies or assume they had a combination of leaks and penetrations?

one would have to assume that if they figured that out, that at minimum the Gestapo would run a series of sweeps and very carefully examine (torture) a large number of people; which would likely find and eliminate a number of key soviet assets

they could never possibly sweep them all, but the soviet intel apparatus would likely suffer collateral damage if the germans go on a paranoia binge

The Soviet apparatus *was* damaged through the war. It didn't alter things all that much, as the Soviets were perfectly able to deceive the Abwehr with or without it, and sometimes Stalin wasn't intent on listening to his intelligence whether it was right or wrong, and given the nature of the WWII USSR, whatever Stalin wanted was done, what he didn't want.....
 
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