An efficient implementation of the Yao's garbled circuits protocol in C for a single AND gate. (In the process of fixing some errors)
Server:-
Run alice_server from the command line of the device where the gate is supposed to be created.
A port number should be provided as a command line argument.
Example
./alice_server <port>
This will allow the program to accept connections on port number of the device.
Client:-
Run bob_client from the command line of the device that needs to know the output.
The ip address of the device running the server and the port number it as accepting connections on should be provided as comand line arguments.
Example
./bob_client <ip address> <port>
This will allow the program to connect to the given port of the given ip address.
ip address should be 127.0.0.1 when both the connections are being run on the same device.
Both server and clients will be asked to input seeds for random number generation.
The client will be asked to enter b (either 0 or 1) which will indicate their choice.
Sources: AES -- https://github.com/kokke/tiny-AES-c/ SHA3 -- https://github.com/mjosaarinen/tiny_sha3
-------------------NOTE-----------------------------------------------------------------
Server:
"alabel.txt" contains the labels for the secret keys for Alice's inputs.
"b_label.txt" contains the labels for the secret keys for Bob's inputs.
"op_label.txt" contains the labels for the output values(op_0 and op_1) of the gate.
"aes.c" and "aes.h" contain implementation of AES that are used in the program.
"sha3.c" and "sha3.h" contain implementation of SHA3 that are used in the program.
"alice_server.c" is the main program that is to be run.
"alice_server" is the executable for "alice_server.c".
"padding.h" is the headerfile which is used for PKCS7 padding in the program.
"alice_gate.c" is where the garbled gate is implemented.
"al_gate" is the executable for "alice_gate.c".
"initvec.txt" contains the generated initialisation vector.
"hash.txt" contains the hashes of the output value labels, op_0 and op_1 which are present in op_label.txt.
"ciph.txt" contains the AES encryptions of the generated output labels (present in op_label.txt).
Client:
"bob_client.c" is the main program that is to be run.
"bob_client" is the executable for "bob_client.c".
"al_input" contains the label corresponding to Alice's input (a0 if Alice's input is 0; a1 if it's 1).
"bob_gate.c" is where the garbled gate is decrypted.
"bob_gate" is the executable for "bob_gate.c".
"initvec.txt" contains the generated initialisation vector.
"hash.txt" contains the hashes of the output value labels, op_0 and op_1 which are present in op_label.txt.
"ciph.txt" contains the AES encryptions of the generated output labels (present in op_label.txt).
"aes.c" and "aes.h" contain implementation of AES that are used in the program.
"sha3.c" and "sha3.h" contain implementation of SHA3 that are used in the program.
For OT (part of alice_server.c):
rsa.h contains common functions required for rsa implementation using gmp
strings.txt contains the two messages, the first corresponding to Bob selecting 0 and the second corresponding to him selecting 1.
- run keygen.c (executable --> keys) to generate e,d and n
public_key.txt contains n in the first line and e in the second line private_key.txt contains n in the first line and d in the second line
- run alice_ot1.c (executable --> alice1) to generate x_0 and x_1
randomx.txt is the file to store randomly generated x_0 and x_1 (on separate lines).
- run bob_ot1.c (executable --> bob1) to generate a random number k, input bit b, and calculate c --> c = (x_b + k^e) mod n
bob_c.txt is the file where c is stored bob_private.txt is the file that stores the random number k and the bit b
- now run alice_ot2.c (executable --> alice2) to calculate v_0 (v_0 = (c – x_0)^d mod n) and v_1 (v_1 = (c – x_0)^d mod n) and encrypted messages m'_0 and m'_1 such that m'_0 = (m_0 – v_0) and m'_1 = (m_1 – v_1)
strings.txt contains two strings (m_0 and m_1, one of which is to be shared by oblivious transfer) enc_messages.txt should contain m'_0 (m'_0 = m_0 - v_0) and m'_1 (m'_1 = m_1 - v_1) the executable for alice_ot2.c is alice2
- now run bob_ot2.c (executable --> bob2) to get the final message, m_b (m_b = m’_b + k)
bob_message.txt contains the final message that Bob receives the executable for bob_ot2.c is bob2