Lets assume I use a PIN on my Trezor for sometime and then change it to a new PIN while keeping the same seed/mnemonic.
And assume someone knows my old PIN, has very sophisticated technical knowledge and access to my Trezor.
Could this person somehow recover a version of the encrypted seed which was encrypted with my old PIN?
Or is the old encrypted seed securely erased from my Trezor if I change the PIN?
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Disregard my previous answer, I was confusing this with wiping the wallet rather than changing the PIN.
Not true @NickW, the user only changes PIN, does not delete the wallet.
As for an actual answer, I don’t know!
I’m asking around. Could depend on the exact implementation. It’s less likely on the Safe family, plus there’s no currently known way to extract anything from the newer STM32U5 chip on the Safe 5
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I mean what is when the only the PIN changes but the seed stays consistent?
Is the Safe 3 also secure concerning this?
Got the answers for you!
They can’t.
It’s not – what is erased is the actual encryption key.
In most encryption systems where you can change the access password, it’s not used for decryption directly. Instead, it encrypts a master key and that is used for actual data encryption.
That way, when you change your PIN or password, you only need to re-encrypt the master key, not every piece of data.
When you change your PIN, the old version of the master key is securely erased, so it can’t be used to decrypt your data.
The older revision of Safe 3 uses a weaker STM32F4 chip, which is vulnerable to a glitching attack, allowing an expert hardware hacker to read out the encrypted form of your seed.
This is not a security problem, because the extracted data is useless without the Secure Element secrets, which cannot be extracted this way.
A newer revision of Safe 3 also uses the more resistant STM32U5.
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Thank you 
Good news
Thats sounds like a very smart solution to handle password derived encryption.
Is there a way to check which version my Trezor’s have? Or can this by checked dependent on the day of there order?
You can use trezorctl get-features, then look for the internal_model field. “T2B1” is the older revision, “T3B1” is newer.
If you don’t have trezorctl, the same info can be found in Suite logs somewhere.
Thank you, I will get it later and then check it
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Sorry for reviving an old thread.
Can you confirm that the Safe 3 (including the bitcoin only version) that’s currently available on your website has the more resistant STM32U5 microcontroller?
I just checked mine with trezorctl get-features and it is T2B1. I thought it was probably an older one since it defaults to the 12 word seed also.
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It’s likely, but I unfortunately cannot confirm. Availability of one or the other is subject to supply levels. The older T2B1 is out of production for quite some time now, but it could still be in stock somewhere.
Even if you get one with 20-word seed card, that does not guarantee that it is T3B1. Product-wise, T2B1 and T3B1 are considered to be the same.
You can either take the chance, or, if you really really want the U5 chip, you’ll have to get the Trezor Safe 5 or 7
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