src

Files

• deps/ - This directory contains the external code from ladnir/cryptoTools on which our codebase depends.
• add.cpp and add.h - This contains the implementation of addition of two masked integers. It is used to replace the + operator in EzPC.
• api.cpp and api.h - This file contains the implementation of the Athos API using FSS. Every extern function called by Athos is implemented here. All the functions work in fixed bitwidth.
• api_varied.cpp and api_varied.h - This file contains the implementation of the SeeDot mixed-bitwidth API using FSS. This means that all the extern functions that SeeDot dumps are implemented in this file. Some API endpoints also contain an implicit implementation of many FSS Gates in the paper.
• ArgMapping.h - Argument parser for LLAMA binary.
• array.h - Contains convenient functions and macros for array allocation and indexing
• comms.cpp andcomms.h - Contains helper functions for transfering data between dealer-evaluator (offline communication) and evaluator-evaluator (online communication). Contains wrappers for transferring different kinds of keys using fundamental transfer of blocks and GroupElements.
• config.h - Contains the compile time configuration macros.
• conv.cpp and conv.h - Contains the implementation of FSS gates for Convolution and Matmul.
• dcf.cpp and dcf.h - Contains the implementation of FSS scheme for DCF from BCG+21.
• fss.h - Public header file for FSS.
• GroupElement.h - Contains the definition of the GroupElement class - a wrapper over uint64_t.
• input_prng.cpp and input_prng.h - Contains the implementation of the input layers which uses a PRNG to compress the keysize required for input layers.
• keypack.h - Contains structures of different FSS Keys.
• lib.cpp, lib.h and lib.ezpc - Contains implementations of functions which can be written as wrappers over API endpoints. lib.cpp and lib.h are generated from the lib.ezpc file by running fssc --bitlen 64 --l lib.ezpc.
• mult.cpp and mult.h - Contains the implementation of multiplication of two masked integers. It is used to replace the * operator in EzPC. It contains both uniform bitwidth (from BCG+21) and varying bitwidth (from LLAMA paper).
• pubdiv.cpp and pubdiv.h - Contains the implementation of FSS gates for Public Division and ARS along with the FSS Gates for Signed Comparison and Interval Containment as the FSS Gate for Public Divison depends on these two gates.
• spline.cpp and spline.h - Contains implementation of FSS gates for Spline Evaluation. This gate is used to implement FSS Gates for ReLU and math functions like Sigmoid, Tanh and Reciprocal-Squareroot.
• utils.cpp and utils.h - Contains helper functions.

Protocols

We have implemented the following protocols from the paper in the respective files:

1. Sign Extension (Figure 1): internalExtend function in api_varied.cpp
2. Truncate-Reduce (Figure 2): internalTruncateAndFix function in api_varied.cpp
3. Signed Multiplication (Figure 3): new_mult_signed_gen and new_mult_signed_eval from mult.cpp
4. Unsigned Multiplication (Figure 4): new_mult_unsigned_gen and new_mult_unsigned_eval from mult.cpp
5. Signed Division (Figure 5): keyGenSignedPublicDiv, evalSignedPublicDiv_First and evalSignedPublicDiv_Second from pubdiv.cpp
6. Mixed Bitwidth Splines (Figure 6): keygenSigmoid and evalSigmoid (name is a bit misleading but same function is used for all math functions with different coefficients) from spline.cpp