What is the maximum duration I can store data on the security chip and expect it to remain intact and reliably retrievable without corruption?
I dug a little and the secure chip’s datasheet says around 15 years.
But I’d like a more complete answer, maybe there’s another hardware component that has a more strict guarantee.
Background story is that different chip technologies store bits in different ways and most of them need to hold a charge to store the bit data. Over time this charge leaks and the data gets corrupted. Would be good to have a page in the Trezor’s docs explaining the expected life of the data in case the device is simply stored for a really long time.
First off, you have to evaluate both the Secure Element(s) and the MCU for durability, because data from all the elements is required to access your wallet.
The Secure Elements don’t actually store your seed, just the decryption keys. So if MCU storage is lost, SE storage is irrelevant.
The lifetime of the data on the MCU is also on the order of 15 years, though I do not have more precise data.
That is because
Trezor is not designed for long term data storage.
If you require reliable storage of your seed material on the order of decades, you should get yourself a metal backup (such as Trezor Keep Metal) and store the seed that way. Then, only when needed, you would recover the backup onto a Trezor.
3 Likes
Thank you @matejcik, that was a complete answer I was looking for.
Unfortunately, a metal backup would store the private key (the mnemonic in fact) in plain, unencrypted way. Anyone with physical access to the metal backup would have access to the coins. I know I could add a passphrase to the wallet and that’s not included in the metal backup. Just wanted to share the pickle.
This problem is also well solved by Shamir backup.
Make a 2-of-3 setup, store one shard at home and two others with medium-trust acquaintances who don’t know each other.
Any one shard is useless: neither your acquaintances, nor any thief who finds any of the backups, can take your money.
However, you can always recover the backup by combining any two of the shards.
1 Like