Questions tagged [snarks]
The snarks tag has no usage guidance.
18
questions
0
votes
0answers
15 views
CRS vs SRS in zk-SNARK
Are Common Reference String (CRS) and Structured Reference String (SRS) is the same in preprocessing phase of zk-SNARK? Is there any difference between them?
1
vote
1answer
72 views
Hash and (MAC) based signatures using zk-SNARK
I was wondering if we could use any general symmetric key MAC, a collision resistant hash $H$ and zk-SNARK (or any general NIZK scheme) to construct a signature scheme. I have a MAC key $k$, which is ...
0
votes
1answer
36 views
Construction of R1CS vs QAP
I have been following the medium post of Vitalik, where he shows step by step how to convert program --> Circuit --> R1CS --> QAP.
I am aware of the Pinocchio protocol, where they utilize the ...
0
votes
1answer
33 views
Difference between a Polynomial Opening & a Polynomial Commitment
Going through the literature led me to think I understood the difference between these two things, but thinking about I am not actually certain. Could you help me correct my definitions of these two ...
1
vote
0answers
51 views
Efficiently prove the correctness of Paillier encryption in or “outside” a zk-SNARK
I'm working with a zk-SNARK library [1] that allows me to prove the correctness of arbitrary arithmetic circuits, and I now want to use these zk-SNARKs to prove that some Paillier [2] ciphertext $c$ ...
3
votes
0answers
56 views
How to construct a circuit in zkSNARK
I have a few questions about how to use zk-snark. Since the basic logic of using zk-snark is:
using a circuit to represent a problem,
generate an R1CS from the circuit,
transform R1CS to QAP and then ...
0
votes
0answers
27 views
How to construct inequality, padding, and truncation in R1CS?
I'm trying to reimplement the zkSNARKs used in zcash using the libsnark library. It involves checking for inequality, and bit manipulation such as padding and truncation. How do I implement those in ...
0
votes
0answers
37 views
Can zk-SNARKs prove satisfiability for NP-hard languages?
In general, I think of zk-SNARK circuits representing a language in NP, meaning it is "computationally easy" to verify. However I was reading about a recent zk-SNARK (Sonic) which has as ...
0
votes
1answer
75 views
Conditional decryption
Is it possible for one party to encrypt some data and have another party (unknown to the first party) view that original data if a certain condition is met?
I cannot find any information about this ...
3
votes
1answer
74 views
libsnark generator toxic waste
I'm looking through the test and examples of libsnark, let's take for example here:
https://github.com/christianlundkvist/libsnark-tutorial/blob/master/src/test-gadget.cpp
at line 19 there's:
...
0
votes
0answers
48 views
two-to-one hash in libsnark, what is it “exactly”?
I'm reviewing this test which prepares a zero knowledge proof of the preimage of an hash:
https://github.com/mariogemoll/libsnark-tutorial/blob/sha256/src/test-knowledge-of-preimage.cpp
In my (wrong) ...
1
vote
0answers
33 views
Fixed variable in Groth16
In the paper On the Size of Pairing-based Non-interactive Arguments by Jens Groth, it is always referred in the equations to satisfy that $a_0 = 1$ and the others $a_1, ..., a_m \in \mathbb{F}$.
I am ...
4
votes
2answers
104 views
Can zksnark prove DLP?
Can one use zksnark to prove the knowledge of a discrete logarithm? In another word, can zksnark (R1CS) encode exponentiation?
5
votes
1answer
241 views
Why invent new hash functions for zero-knowledge proofs?
Recently, new hash functions were invented. Their primary purpose is serving the needs of zero-knowledge proof systems. I'm talking about Poseidon-256, Starkad-256, etc. See the paper.
What is the ...
1
vote
1answer
89 views
Examples of flattening code to create an R1CS
When preparing logic for use in a zkSnark, one needs to first "flatten" the code so it can be written as a series of constraints.
I'm finding it hard to find examples of doing this. For instance, how ...
0
votes
0answers
107 views
Converting R1CS to QAP - checking the last step
from reading Vitalik Buterin's excellent post on creating a QAP from an R1CS, I understood to translate a function into three groups of vectors, the number of vectors being the number of "gates" or ...
0
votes
1answer
48 views
Is security of zk-SNARKS related to the size of the arithmetic circuit they evaluate?
In the context of zk-SNARKS, we are given an arithmetic circuit $C$, public outputs $y_1, \ldots, y_n = \mathbf{y}$ and some public inputs $x_1, \ldots, x_ℓ$. The prover wants to prove knowledge of ...
0
votes
0answers
46 views
How to encode SHA-256 as a quadratic span program?
I'm trying to understand the step-by-step zkSNARK's generation process for proving the knowledge of the hash pre-image (as in this example). However, I don't understand how exactly SHA-256 is turned ...
