It's a bit sad that when one searches for "Who broke the Enigma device first" it's typically Alan Turing whose picture pops up first.
The situation is much better than 20-30 years ago, where the Polish mathematicians were lucky if they were mentioned at all.
Personal anecdote: there's (or was) an Enigma device on display at the Computer History Museum in Mountain View ~2010. I asked the person who toured us (or maybe in charge of this area of the museum) the same question, and the answer was "British, in Bletchley Park". When I gave them funny looks, they realized their mistake and said something to the tune of "ahhh... yeah, and also Polish did some small initial work".
Much of Polish involvement in WW2 was extremely heroic and intelligent but not well-known. Turing's great achievement was to build on the knowledge shared by Polish mathematicians, to break the more sophisticated wartime Enigma codes, which no one could yet decipher.
To be fair, what the Poles broke was early Enigma, same idea but not so close to the late-war Enigma that these machines need to target. The M4 Enigma on a late war U-boat is too sophisticated to be practically attacked with the pencil and paper approach the Poles were taking just prior to and then during initial periods of the War.
On the one hand a museum of flight which doesn't mention the Wright Brothers is stupid, but on the other hand if they act as though from the Wright Flyer to an A320 or an F35 is just trivial refinements that's not telling an accurate story either, you want to mention e.g. Frank Whittle and ideally the larger context (Ohain in Germany also invents this engine, before Whittle, but by the time he gets it actually working Germany is losing the war anyway)
Edited to add: It's actually razor thin the difference between what would have been enough to defeat Allied cryptanalysis and what Enigma actually does. If tradecraft by German military groups had been 100% there's every chance Ultra would have gone nowhere, and we'd see Bletchley Park, if it was remembered at all, as a failure. "Why did the British think they had any chance?"
Fortunately Germans are human and they screwed up. They'd send similar messages with the same encryption, they'd forget to choose random keys and then remember and begin again with the new keys, they'd be lazy and use the simplest change rather than fully randomising. All things you'd expect humans to get wrong, but it's nice that they did or things might have turned out very differently.
If you are the slightest bit interested in codebreaking, visiting Bletchley Park is an absolute delight. I cannot recommend it highly enough. The tech is still impressive today, and even more impressive is the human side of it. The huts are still there (mostly) and a few have be renovated so you can tour them. There's also the National Museum of Computing right next door with a replica Colossus machine.
You can watch a number of demos and tours on Youtube, but seeing a Bombe machine decrypt your own Enigma encoded message in person is pretty impressive.
NB: Worth checking (I think I've managed to get this wrong twice so far!) whether both the Bletchley Park museum and the National Museum of Computing are open, since their opening times don't always overlap well.
We actually took a day trip with a team I had at a previous employer to see the NMC, but turned out it was closed, the Bletchley Park museum is cool, and we needed to see the plaque you mentioned because that team had several Polish people who were integral to our success (hi Monika if you're reading!), but we specifically intended to look at the NMC because it's a team of software engineers, so that was a little disappointing.
A Bombe doesn't exactly "decrypt" messages. What happens is the bombes are eliminating impossible settings. So you put in a message, and a guess about part of what it says, and the Bombe tries keys, rather like brute forcing a password. "ABCDE, No. ABCED, No, ABDEC, No" and so on. The way Enigma works makes it possible to rule out some keys if you guessed part of the message. When it can't eliminate a key, the machine stops, "CABDE... Maybe". A team of mostly women would try these "stops". Maybe CABDE produces gibberish, the machine is set running again, next is "DEABC" and this produces a message that looks like human text, send it to the German translators in another hut. [ The actual keys in Enigma are not five ASCII letters ]
I have Enigma by Hugh Sebag-Montefiore (https://www.amazon.com/Enigma-Battle-Code-Hugh-Sebag-Montefi...) except in incredibly nice Folio Society edition. It is meticulously researched and covers all the fun parts of Bombes and programming. The appendixes do step by step algorithm explanation of how this work. Tons of unsung heroism in the seas with the capture of various machines from U boats and ships.
An excellent book that does a barely-under-surface-level touch on cryptography through history, which touches on this as well, is The Code Book by Simon Singh. Saw it in the local library, and wasn't expecting to be super intrigued, as I already understand a lot of the fundamentals of cryptography. Turns out it was less of a "how cryptography works in detail" book, and more of a "how cryptography has been applied and innovated on throughout major historical periods" book.
I’m currently reading the biography of Alan Turing by Andrew Hodges and just so happen to currently be in the chapters discussing the history and operation of the Bombes. Funny to see this pop up now!
The situation is much better than 20-30 years ago, where the Polish mathematicians were lucky if they were mentioned at all.
Personal anecdote: there's (or was) an Enigma device on display at the Computer History Museum in Mountain View ~2010. I asked the person who toured us (or maybe in charge of this area of the museum) the same question, and the answer was "British, in Bletchley Park". When I gave them funny looks, they realized their mistake and said something to the tune of "ahhh... yeah, and also Polish did some small initial work".
Proof: https://www.computerhistory.org/tdih/July/15/