Mor Weiss

Probabilistically Checkable Proofs of Proximity with Zero-Knowledge

A probabilistically Checkable Proof (PCP) allows a randomized verifier, with oracle access to a purported proof, to probabilistically verify an input statement of the form “x ∈ L” by querying only few bits of the proof. A PCP of proximity (PCPP) has the additional feature of allowing the verifier to query only few bits of the input x, where if the input is accepted then the verifier is guaranteed that (with high probability) the input is close to some x′ ∈ L.

Multi-Key Searchable Encryption, Revisited

We consider a setting where users store their encrypted documents on a remote server and can selectively share documents with each other. A user should be able to perform keyword searches over all the documents she has access to, including the ones that others shared with her. The contents of the documents, and the search queries, should remain private from the server.

Making the Best of a Leaky Situation: Zero-Knowledge PCPs from Leakage-Resilient Circuits

A Probabilistically Checkable Proof (PCP) allows a randomized verifier, with oracle access to a purported proof, to probabilistically verify an input statement of the form “\(x\in L\)” by querying only few bits of the proof. A zero-knowledge PCP (ZKPCP) is a PCP with the additional guarantee that the view of any verifier querying a bounded number of proof bits can be efficiently simulated given the input x alone, where the simulated and actual views are statistically close.

How to Construct a Leakage-Resilient (Stateless) Trusted Party

Trusted parties and devices are commonly used in the real world to securely perform computations on secret inputs. However, their security can often be compromised by side-channel attacks in which the adversary obtains partial leakage on intermediate computation values. This gives rise to the following natural question: To what extent can one protect the trusted party against leakage?

Zero Knowledge LTCs and Their Applications

Locally testable codes (LTCs) are error-correcting codes for which membership in the code can be tested by probing few symbols of a purported codeword. Motivated by applications in cryptography, we initiate the study of zero knowledge locally testable codes (ZK-LTCs). ZK-LTCs are LTCs which admit a randomized encoding function, such that even a malicious tester which reads a large number of codeword symbols learns essentially nothing about the encoded message.