WI: Nazis discover Enigma broken in 1939?

An idea I'm kicking around: what if during the invasion of Poland the Germans had discovered the full extent of the Polish analysis of the Enigma machines?

IOTL the Germans believed that breaking Enigma would be impractical, and were fairly careless about procedures. Discovering that the Poles could read their early machines and that with some effort the Allies would be able to read messages from the new (as of 1939) machines would be quite a shock.

The Germans will, naturally, take steps to improve their encrypt methods and procedures. This will greatly hamper (though not stop) Allied SigInt. With only minimal and erratic ULTRA intelligence, how is the war changed?
 
Fatherland had the Germans learning about the British cracking the enigma code, which was one of the factors (along with Heydrich living) that led to a Nazi victory.
 
Fatherland had the Germans learning about the British cracking the enigma code, which was one of the factors (along with Heydrich living) that led to a Nazi victory.

Let's keep the Axiswank to one thread at a time, please?

Knowing their codes are vulnerable doesn't conjour a massive fleet of landing craft to invade the UK, or thousands of trucks (loaded with winter clothing while you're at it) for the Eastern Front.
 

mowque

Banned
Makes the naval war and the one in North Africa quite different. However, might not the Allies just break whatever the Germans cook up?
 
Makes the naval war and the one in North Africa quite different. However, might not the Allies just break whatever the Germans cook up?

I'm assuming (this is a point I would appreciate feedback on) that once the Germans know that Enigma can be broken, they'll tighten up procedures and increase the number of wheels on the machines, etc. This will make things MUCH harder for the Allied code-breakers. The Allies will still be able to do traffic analysis of course (though the Germans will probably rely more on landlines), and will still be able to read bits here and there, but not the heavy penetration of OTL.
 

Anaxagoras

Banned
Massive butterflies that could potentially lead to a German victory. By itself, it will increase German effectiveness in the Battle of the Atlantic considerably, and this might be enough to logistically strangle Britain.
 
Fatherland had the Germans learning about the British cracking the enigma code, which was one of the factors (along with Heydrich living) that led to a Nazi victory.

Fatherland is one of the worst Alternate History books I have ever read. Poor plot, no ending, simple explanations to alter history.

My personal favorite was where the USA decides not to nuke Germany because the Germans exploded a rocket over New York City...stupid stupid stupid
 
While ULTRA was helpfull in the Atlantic, it was by no means critical. It would mean the RN has to fight more convoys through (remember, there was a gap of nearly a year in 1942 when they couldnt decode Enigma anyway...), but by 1943 they can wreck any uboats sent against them.
 
my timeline Manstein in Africa's first installment explores this; and indeed has the Axis bait the RN into a trap where they lose a lot of ships in coordinated air strikes

the germans had several rl oportunities where they where skirting around the edge of their problem;

1. intel captured in poland
2. certain british air and sea movements being suspiciously well timed in 1940 (even beyond radar)
3. rommel was utterly convinced his signals network was compromised (although he didn't understand why) so he did a ton of stuff by courier/radio silence or just ignored radio orders from rome and berlin... he could have read the problem differently
4. rommel had several opportunities during different battles where he could have captured 8th army hq which might have left enough documents to put him on the track that his signals network was compromised
5. kesselring nearly pushed the 5th army back into the drink during operation avalanche, if he overran them or compelled a hasty evac of the army hq staff, its possible he could have captured vital documents that could have let him on to ultra... ditto for anzio
6. the allies did telegraph their punchs a bit obviously in some battles (like during the battle of averanges and the battle of mortain) which could ahve set off alarm bells
7. 7th panzer had an outside chance of being overrun in 1940 which would have let a fair amount of enigma gear fall into British hands which might have increased german paranoia about its viability

the question is how aggressively do the germans respond

periodically they got paranoid about their signals security and would increase the difficulty of the enigma patterning system (ie extra wheels) which would put the allies out of the loop for several months; but wasn't a long term solution

the pod i used; and like for the scenario because it solves two birds with one stone (ie the germans find out they have a problem, and develop a solution to the problem):

namely the germans and italians conduct an operation where there is minimal coordination between the two armies; and the german element of the operation gets roughly handled due to their surprise not existing whereas the Italians have a walkover... operation felix or maybe hercules could have produced a situation like this that might have set off alarm bells, and the solution is obvious; use the italian system which was utterly unbreakable (they used 1 time cipher pads which where very popular with the kgb and the nsa in the 70s and 80s and are a huge pain in the ass but totally reliable)

the ironic thing is that italian codes where never broken during the war; and rommel thinking the network was compromised made them switch to enigma :p


is it a game changer; yes

war winner; no... if anything following some initial german successes it might actually help the allies not to have ultra... they where overly dependent on it and it made them complacent and too conservative in their approach... there where instances where their human intel was better than ultra anyway (and ignored due to their love of ultra) such as the battle of the bulge and market garden
 
is it a game changer; yes

war winner; no... if anything following some initial german successes it might actually help the allies not to have ultra... they where overly dependent on it and it made them complacent and too conservative in their approach... there where instances where their human intel was better than ultra anyway (and ignored due to their love of ultra) such as the battle of the bulge and market garden

Could it change the game enough to allow the Germans to make decisions that would lead to them winning the war?
 
Could it change the game enough to allow the Germans to make decisions that would lead to them winning the war?

Probably not. The war was lost for Germany by poor decisions made at the command level, not the kind of tactical decisions that uncompromised communications make a huge difference with.

Decisions such pressing on to Moscow in December of 1941, to fight for Stalingrad street by street in 1942, to not even attempt to evacuate the Africa Corps in 1943. The list goes on.

I agree with Blairwitch that the Germans knowing their codes were broken would have made a significant difference in Battle for the Atlantic. The problem is that the Allies can always produce such a surfeit of destroyers and carriers that U-Boats alone are not going to be able to effectively close the sea lanes that supplied GB. That can sink more merchantmen, and more critically tankers, but other than making British civilians suffer a bit more and delaying a few offensives, that does not change the "big picture" enough to allow the Germans to win the war.

If the shoe was on the other foot, and the Germans managed through some intelligence coup to decrypt a comparable amount of Allied Intel to what the Allies decrypted of German Intel during the war...that could be a war winner.
 
Let's keep the Axiswank to one thread at a time, please?

Knowing their codes are vulnerable doesn't conjour a massive fleet of landing craft to invade the UK, or thousands of trucks (loaded with winter clothing while you're at it) for the Eastern Front.

No, but an early discovery of that vulnerability means the Germans either beef up the coding machine once again, or get twice as cautious about the information they send through it.


This in turn makes battle of the Atlantic a lot more difficult, as the u-boote once again shroud themselves in the fog of war.

Greater u-boot success hampers the Allies war effort, from troop shipping to supplies bound for Russia and England. Build-up in Great Britain gets slower as a result, either because of losses or because additional precautions.

Depending on the the extent to which the Allied war effort is hampered, Germany might get a consequent respite.
 

Cook

Banned
No, but an early discovery of that vulnerability means the Germans either beef up the coding machine once again, or get twice as cautious about the information they send through it.

Or realise that any mechanical encoding system is fundamentally vulnerable and move away from it.
 
Could it change the game enough to allow the Germans to make decisions that would lead to them winning the war?

probably not

intel for the allies wasn't so based on ultra that they would lose the war if they didn't have it

the allies had a VERY extensive human intel network (as did the russians)... nazi's had a tendency to create resistance groups who where quite ruthless and willing to die to bring intel to the allies on a wide variety of topics

ultra was useful in the battle of the atlantic and in sinking rommel's supply ships but it wasn't so useful that the allies couldn't win these events without it... losing ultra perhaps delays these things by some months but its not a war changer

keep in mind that despite the edge that ultra gave, the allies where prone to misread it, ignore it, favor it wrongly against human intel, or get fooled by it when the germans gave radio orders for one thing but the commanders on the ground where told something different via courier or telephone

IMO even if the Germans totally scrap it and replace it with a system that can't be broken during the war (a la the Italian system) it actually helps the allies long term since they won't be so complacent with it
 
Actually the German's did discover that the Poles could read Enigma. See http://www.nsa.gov/public_info/_files/tech_journals/Der_Fall_Wicher.pdf

Mostlyharmless, that link won't open for me. Would you be kind enough to summarize the highlights?

my timeline Manstein in Africa's first installment explores this

Sigh. One of these days (OK, weeks) I need to sit down and read through the Manstein stories. I don't suppose you have a word/PDF/txt file of the earlier books?

No, but an early discovery of that vulnerability means the Germans either beef up the coding machine once again, or get twice as cautious about the information they send through it.


This in turn makes battle of the Atlantic a lot more difficult, as the u-boote once again shroud themselves in the fog of war.

Greater u-boot success hampers the Allies war effort, from troop shipping to supplies bound for Russia and England. Build-up in Great Britain gets slower as a result, either because of losses or because additional precautions.

Depending on the the extent to which the Allied war effort is hampered, Germany might get a consequent respite.

Certainly the U-boats will sink more ships and suffer fewer losses. The problem, however, is that by... wanna say mid-1943 or so engaging a convoy was very nearly a suicide mission. That wasn't ULTRA, that was improved technology, tactics, and more plentiful equipment. The Liberty fleet, DEs and CVEs all dropped off in 1944 because the Allies had enough. Had the Battle of the Atlantic gone worse, the Allies simply would have kept the production lines running through 1944 at full speed. That means fewer landing craft, late-model DDs, etc., which might conceivably delay Overlord, but it won't prevent it.

I'm happy to accept that knowing Enigma was broken would prolong the war, but I can't see it changing the ultimate outcome.
 
Mostlyharmless, that link won't open for me. Would you be kind enough to summarize the highlights?



Sigh. One of these days (OK, weeks) I need to sit down and read through the Manstein stories. I don't suppose you have a word/PDF/txt file of the earlier books?



Certainly the U-boats will sink more ships and suffer fewer losses. The problem, however, is that by... wanna say mid-1943 or so engaging a convoy was very nearly a suicide mission. That wasn't ULTRA, that was improved technology, tactics, and more plentiful equipment. The Liberty fleet, DEs and CVEs all dropped off in 1944 because the Allies had enough. Had the Battle of the Atlantic gone worse, the Allies simply would have kept the production lines running through 1944 at full speed. That means fewer landing craft, late-model DDs, etc., which might conceivably delay Overlord, but it won't prevent it.

I'm happy to accept that knowing Enigma was broken would prolong the war, but I can't see it changing the ultimate outcome.


Book one has the operations where the Germans discover their problem and bait the RN

When I get a chance I'll copy and paste it and request admin to post it to the finished timeline section so you can read it without having to sift through the hundreds of comments
 
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