Score:0

Prove that string exists in source file of sha256 hash

br flag

How to prove that hashed data includes specific string without exposing rest of the string?

Practical example is calculating digest to be signed of the PDF file and before signing the digest we need to make sure that this PDF contains specific part in the middle. Whole PDF contents can not be show to the signing application.

When the signing application is sure that PDF indeed contains specific part then the signature is authorized.

Marc Ilunga avatar
tr flag
Perhaps a Merkle tree, combined with an appropriate definition of what data is consider as leaves. https://en.m.wikipedia.org/wiki/Merkle_tree
Maarten Bodewes avatar
in flag
Of course you'd also have to save the data within the branches of the tree, and those could be used to brute-force the rest of the data - if that's feasible.
br flag
How would it work with data in the branches? There are data blocks L1, L2, L3 and we need to make sure that hash of concatenation L1+L2+L3 contains data block L2 without seeing L1 and L3
mangohost

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.