How to generate a circuit containing out-of-circuit or fixed information?

[supercrush]

I want to generate a simple circuit, which appends a single '0' (out-of-circuit information) at end of the bitstream.

Code:

    Integer in(1,1, ALICE);
    Integer p(1,0,PUBLIC);  //out-of-circuit information
    Integer out(2,0,PUBLIC);
    

    out[0] = in[0];
    out[1] = p[0];
    std::cout << out.reveal<string>(PUBLIC) << std::endl;

generated circuit:

3 4
1 0 2
                                                                                                                                                                                              
2 1 0 0 1 XOR    
2 1 1 0 2 XOR
2 1 1 0 3 XOR

x₁ = XOR(x₀, x₀) // result is 0 x₂ = XOR(x₁, x₀) // result depends on x₀ x₃ = XOR(x₁, x₀) // result depends on x₀

The output doesn't contain any information of out-of-circuit information. The result of the two outputs x₂, x₃ is always the same as the input x₀ and the out-of-circuit information is missing. What is the correct way to generate a circuit containing out-of-circuit information like appending a fix '0' at the end of the bitstream?

[wangxiao1254]

All constants are hardcoded to minimize the number of gates. All XOR gates here are only to gather outputs.

[supercrush]

Hi. Thank you very much for your reply!

There is no problem in directly running my previous snippet when creating two instances.

However, if I generate a circuit and load it to compute the result, the outcome is incorrect. The outcome of both bits depends on wire[0] as mentioned above, i.e., in[0] (x₀). When a[0] = wire[0]=1, the result will be 11, and vice versa. Code snippet:

    Integer in(1,1, ALICE);
    Integer out(2,0,PUBLIC);
    std::string filepath = "./circuit.txt";
    emp::BristolFormat cf(filepath.c_str());
    cf.compute(out.bits.data(), in.bits.data(), nullptr);
    std::cout <<out.reveal<string>() << std::endl;

In other words, is it not suitable for loading such generated bristol format circuits and running in sh2pc or ag2pc? How can I run such an application (appending constant) in ag2pc. I assume it requires a circuit to run in ag2pc.

[Sherlock-feng]

Hi, I have a problem. Readme doesn't show how to use the library. Besides, I don't know where is the interface in the library and how to run my own code. Can you tell me which step to follow to run the code like you did?