# Questions tagged [garbled-circuits]

Garbled Circuits are used in Secure Multiparty Computation

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### Understanding Half-Gates for Garbled Circuits

Currently I am reading though Two Halves Make a Whole and understand the basics of generator half-gate and evaluator half-gate. The generator half-gate can be used when the garbler knows the input to ...
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### Masking Bits in n-party Garbled Circuit

Let us consider the scenario where there are n-1 garblers and a single evaluator. The garblers together need to generate a garbled circuit. We use a distributed garbling protocol such as [BLO16] and ...
1 vote
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### n-Party Garbled Circuit

Yao introduced a famous notion of securely computing any function between 2 users using a concept of Garbling circuit. How can this idea be extended for n-party case? That is there are n-1 garblers ...
1 vote
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### Is it secure for A to allow B to run a garbled circuit twice with different inputs? [duplicate]

I was reviewing past exam questions and came across this one: Is it secure for A (the garbler) to allow B (the evaluator) to run a garbled circuit twice with different inputs? They aim to compute the ...
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### Choosing $C_0$ to make second row zero for Garbled Row Reduction (GRR3)

In GRR3,we make the first row of the Garbled table to be zero by choosing a special value of $C_1$. Why don't we make the second row also zero by choosing a special value of $C_0$?
259 views

### LPN Encryption Homomorphism

Trying to understand the LPN encryption in this paper: https://eprint.iacr.org/2021/120.pdf. From Definitions 4 and 5, ciphertext is $c=C\cdot s\oplus e\oplus G\cdot m$ and the paper says the LPN ...
• 149
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### 2-PC vs Secure function evaluation vs private function evaluation

I'm currently confused about the distinctions between two-party computation (2-PC), secure function evaluation, and private function evaluation. Additionally, I came across the term secure circuit ...
1 vote
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### The reference of external values in Garbled Circuit

Is anyone aware of the source for a technique that incorporates external wire values into Garbled Circuits? I have come across this technique, which can be found here. However, I was unable to locate ...
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### why the intermediate labed value should be encrypted in Garbled Circuits?

I do not know why the intermediate value (for example, W5, W6) should be encrypted?? I think the encryption (random value) only needs in the input process (e.g. w1, w2, w3, w4).
1 vote
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I have been examining the Gazelle paper, which focuses on secure inference protocols. One section constructs a Garbled Circuit using inputs cx, sx, and sy to compute the ReLU function in neural ...
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1 vote
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### How is a message $\mu$ encrypted in a witness encryption scheme below? What does C(x) = 1 mean below?

I was reading this paper, where I came across the following statement on Pg 4 under the Homomorphic Commitments: A witness encryption scheme, associated with a NP language, consists of an encryption ...
165 views

### Garbled circuit and secret sharing

Recently, I was reading the paper One Hot Garbling published on CCS 2021. I noticed a sentence in it: In this work, we forgo the standard GC notation of garbled labels in favor of garbled sharings of ...
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### How can Garbled Circuits be utilized to reduce the round complexity of GMW?

I've been reading this set of notes on some topics in MPC and am having difficulty understanding the transformation the authors make in order to reduce the round complexity of the GMW protocol through ...
156 views

### Conditional Boolean circuits

I have two questions I couldn't find straightforward answers to after many searches. (1) We can perform 2-party MPC over arbitrary functions using Garbled Circuit. To do that, we first need to convert ...
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### Binary Secret Sharing vs Garbled Circuits

In Privacy-preserving machine learning, GC is usually used for privacy operation such as ReLU(x) where sign(x) needs to know. However, binary secret sharing also supports such computation via ...
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### Reusing input labels in half-gate construction

In the half-gate construction of garbled circuits, is it possible to garble multiple instances of a circuit while re-using certain input labels? Suppose Alice and Bob would like to compute a function ...
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### Multiple input AND/OR gate evaluation

In MPC, AND and XOR gates are two mostly used gates. However, most of the solutions (Garbled Circuit or Boolean Secret Sharing) considered these gates having 2 input wires and 1 output wire. I am ...
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1 vote
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### How to encrypt in garbled circuits

I’ve read a lot of articles and a lot of questions here to understand how the encryption is done in garbled circuits. As I understand double encryption is to encrypt the gates and the truth table. The ...
140 views

### How Cut-and-Choose can leak information?

I'm currently reading the book "A Pragmatic Introduction to Secure Multi-Party Computation". On pages 103-104 I came across the following related to the Cut-and-Choose technique: If $P_2$ ...
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1 vote
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### Will two-party garbled-circuit based protocol have any security issue when inputs are from multiple parties?

If the inputs for a garbled circuit are from multiple parties, can parties (not garbler, not evaluator) obtain the labels corresponding to its input from the garbler via oblivious transfer then send ...