secure-p-signature-linkage

This code demonstrates secure matrix multiplication using the systolic matrix encoding. A talk by the author describing the mathematical background can be seen here. SEAL is used for homomorphic encryption.

Prerequisites

The only prerequisite is SEAL. Build that according to the instructions. You do not need to make install it unless you want to for other purposes. In any case, make a note of the location of the libseal.a library. If it is not located at /usr/local/lib/libseal.a, then set the environment variable LIBSEAL_PATH to the actual path when calling make below.

Building

To build, you need a C++ compiler with support for C++17, OpenMP and PThreads. This is the case for any modern version of GCC or Clang. To build, simply run

$ make

or, if your libseal.a is in a non-default location,

$ LIBSEAL_PATH=path/to/libseal.a make

Running

The build process produces a shared library libseclink.so and an executable file secure-linkage. The easiest way to use the library is via the Python interface. One proceeds as follows. Run your favourite Python interpreter in the build directory and set the load library path at the same time:

$ LD_LIBRARY_PATH=. python3
Python 3.6.7 (default, Oct 22 2018, 11:32:17)
[GCC 8.2.0] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>>

Now load the library and run the test function:

>>> import seclink
Loaded lib <cffi.api._make_ffi_library.<locals>.FFILibrary object at 0x7fdfec1efb00>
>>> seclink.run_test(log = print)
creating context... 103.6ms
generating keys... 1727.1ms
encrypting 2048x512 left matrix... 567.9ms
encrypting 512x2 right matrix... 1.2ms
multiplying encrypted matrices... 4597.8ms
decrypting 2048x2 product matrix... 11.1ms
result is correct?  True
True
>>>

Have a look at seclink.py to see what is happening here. You can pass different matrix dimensions to run_test(...) to see the effect on the run time.

You can also run the secure-linkage program from the build directory which is very similar to the Python function above. It produces the following output

$ ./secure-linkage
/ Encryption parameters:
| scheme: BFV
| poly_modulus_degree: 4096
| coeff_modulus size: 109 bits
| plain_modulus: 40961
\ noise_standard_deviation: 3.2

encrypting left...
encrypting right...
multiplying...
decrypting...
cleaning up...

See here for what the code is doing.

Docker

A Dockerfile is provided and can be used to build a Docker image in the usual way. A prebuilt Docker image, which runs seclink.run_test() as above and leaves the user in the Python session, is available by running

$ docker run --rm -it data61/secure-pprl:latest

Note that running the code through Docker will result in a performance decrease of about 10% compared to running natively.

Author and licence

The principal author of secure-p-signature-linkage and the associated research is Dr Hamish Ivey-Law (@unzvfu). Email: hamish.ivey-law (at) data61.csiro.au

secure-p-signature-linkage is copyright (c) Commonwealth Scientific and Industrial Research Organisation (CSIRO).