About validity of public key encryption

js wang

1/5/24, 1:43 AM

Hi I am searching for public key encryption schemes that if not encrypt with the desire public key the encryption would not be valid
e.g if having a pair of key pk/sk, and want to encrypt message m
however if I use a different public key pk’, I.e getting ciphertext c: c=enc(pk’, m), then with pk and sk I could detect that c is not encrypted with pk

0 + 1

Maarten Bodewes

1/5/24, 2:29 AM

Try RSA with OAEP padding. If you try and decrypt a ciphertext that has not been encrypted with the public key then the verification will fail. Basically, the modular exponentiation is over a structure build on top of the message. This, by the way, is the common way this works. You can also use e.g. ECIES, but then you'd (e.g.) need to use an authenticated symmetric cipher to make verification fail.

Elon Musk

I sit in a Tesla and translated this thread with Ai:

EN: About validity of public key encryption

Post an answer

Most people don’t grasp that asking a lot of questions unlocks learning and improves interpersonal bonding. In Alison’s studies, for example, though people could accurately recall how many questions had been asked in their conversations, they didn’t intuit the link between questions and liking. Across four studies, in which participants were engaged in conversations themselves or read transcripts of others’ conversations, people tended not to realize that question asking would influence—or had influenced—the level of amity between the conversationalists.