Understanding the circuitry: Priority Encoder

[zak100]

Hi,

I am trying to understand the circuitry provided at:

 

MPCircuits: Optimized Circuit Generation for Secure Multi-Party Computation

 

The circuit is :

 

Somebody please guide me what is the purpose of priority encoder in this circuit and how it works in the context of stable matching  problem.

Is it doing some encryption/ decryption?

 

Zulfi.

 

 

 

Edited April 22, 2020 by zak100

[Strange]

Does this help: https://en.wikipedia.org/wiki/Priority_encoder

Actually, it might not because the first paragraph is incomprehensible. But the second paragraph is clearer. Basically, it has a number of input bits which are in priority order, and it tells you the highest priority bit that is set.

I'm afraid I am not going to try and work out what it does in that system. Presumably it chooses the next person to be processed.

[zak100]

Hi,

Thanks for your input. We have two groups. Why we call the circuit as multipart circuit?

 

Zulfi.

[Endy0816]

15 minutes ago, zak100 said:

Hi,

Thanks for your input. We have two groups. Why we call the circuit as multipart circuit?

 

Zulfi.

Multi-party not multipart. They're referring to more than one person being involved.

https://en.m.wikipedia.org/wiki/Secure_multi-party_computation

[zak100]

Hi,

Thanks for your reply and link. If there is no encryption, how are we having security in the above circuitry?

 

Somebody please guide me.

 

Zulfi.

[zak100]

Hi,

I got following text from the paper:

Quote

In secure stable matching, the match list is computed while
keeping the preference lists private to their respective owners.
This problem has been studied in the recent literature [21],
[22] where the secure stable matching problem is reduced to a
two-party secure computation scenario. Each individual XORshares
her preference list and sends it to two non-colluding
servers who perform the secure computation. However, stable
matching is inherently a multi-party problem and the assumption
of two non-colluding servers may not be feasible in
practice. To the best of our knowledge, we provide the first
solution for multi-party secure stable matching.

I can't understand why its multi-party circuit? Its inputting two groups. But how its performing n * n  computation instead of 2 * 2 computation.

 

Somebody please guide me.

Zulfi

[Strange]

Just now, zak100 said:

I can't understand why its multi-party circuit? Its inputting two groups. But how its performing n * n  computation instead of 2 * 2 computation.

 

n = 2

[zak100]

Hi,

Thanks for your response.

Don't we have two groups in multi-party computation? Figure shows that the circuit can only input two groups. How in case of multi-party computation, the circuit uses the two groups to do n * n computation?

 

Zulfi.

[zak100]

Hi,

Sorry correcting above:

 

Can't we input only two groups in the above figure? Figure shows that the circuit can only input two groups. How in case of multi-party computation, the circuit uses the two groups to do n * n computation?

Zulfi.