[kenniskrag]

> Much like the other products we analyse, 1Password lacks authentication of public keys. This trivially enables sharing attacks similar to BW09, LP07 and DL02, something that the 1Password whitepaper...

> IMPACT. Complete compromise of vault confidentiality and integrity. The adversary can read and decrypt all vault con- tents encrypted after the attack, including passwords, credit card information, secure notes, and other sensitive data stored in the vault. Similarly, they can inject new items into the vault after the attack. REQUIREMENTS. The client fetches key material from the server, for example due to the user logging in on a new device. If executed on a non-empty vault, the attack results in the client losing access to all items already in their vault, while leaking any new items added to the vault after the attack took place. If the attack is executed at the time of vault creation, the attack is effectively undetectable by the client, since it cannot distinguish between a ciphertext it created and the ciphertext created by the server during the attack. PROPOSED MITIGATION. A straightforward mitigation is to have the client sign vault keys using the RSA private key in the keyset before encrypting them with the RSA public key. Ideally, two different key pairs would be used for...

from the paper: https://eprint.iacr.org/2026/058.pdf