I tried out HElib, a library for homomorphic encryption, written in C++.
I simplified the instructions in the HElib INSTALL.md. I don't plan to run any huge computations. It's all about trying out the library and computing a first example.
Last version I tried: HElib v2.2.1 (1-Feb-2022)
- HElib on Github https://github.com/homenc/HElib
- Documentation of the library: https://homenc.github.io/HElib/
- The math behind the HElib: HElib-design.pdf
- HElib namespaces to keep track of all the function, class, and variable names in various libraries
- Pre-compiled examples: https://github.com/homenc/HElib/tree/master/examples
Steps for
I'm following the instructions in the HElib INSTALL.md.
Latest version I tried on Mac was v2.0.0; see Ubuntu for v2.2.1.
Check pre-reqs on MacOS:
- Apple clang >= 11.0.0
$ clang -v
Apple clang version 12.0.0 (clang-1200.0.32.2)
Target: x86_64-apple-darwin19.6.0
Thread model: posix
InstalledDir: /Library/Developer/CommandLineTools/usr/bin
- Xcode Command Line Tools
xcode-select --install
- cmake >= 3.17.3
brew install cmake
CMake generates Makefiles which enable you to compile the application with gcc (link to cmake intro)
Download and compile the library:
git clone https://github.com/homenc/HElib.git
cd HElib
mkdir build
cd build
cmake -DPACKAGE_BUILD=ON ..
make -j4 # seems to be good enough on a small Macbook
sudo make install
The helib library is now installed in /usr/local/./helib_pack/.
Jump to the next chapter to see how to work with an example.
Check pre-reqs on Ubuntu:
- cmake
- g++ (see warning below)
- patchelf >= 0.9
- m4 >= 1.4.16
- GMP and NTL libraries
- pthreads (new!)
WARNING: I had compilation issues on my new machine which came with a Tiger Lake Intel processor. So I had to go to g++ version 10. See Issue 1 for the steps I took to convince my machine to work with g++ version 10 instead of 9 which seems to be the default as of now in Ubuntu 20.04.
sudo apt-get update
sudo apt-get install g++ cmake patchelf m4 libgmp-dev libntl-dev libpthread-stubs0-dev
Download and compile the library:
git clone https://github.com/homenc/HElib.git
cd HElib
mkdir build
cd build
cmake -DPACKAGE_BUILD=ON ..
make -j16
sudo make install
The helib library is now installed in /usr/local/./helib_pack/.
First check that the library is called correctly.
I create a little demo file
mkdir helibdemo
cd helibdemo
vi helibdemo.cpp
with the following content:
#include <helib/helib.h>
int main() {
return 0;
}
In addition I create a cmake file CMakeLists.txt.
### simplified copy of the CMakeLists.txt file of the HElib examples
cmake_minimum_required(VERSION 3.10.2 FATAL_ERROR)
## Use -std=c++17 as default.
set(CMAKE_CXX_STANDARD 17)
## Disable C++ extensions
set(CMAKE_CXX_EXTENSIONS OFF)
## Require full C++ standard
set(CMAKE_CXX_STANDARD_REQUIRED ON)
project(HELibDemo VERSION 1.0)
add_executable(helibdemo helibdemo.cpp)
find_package(helib ${HELIB_VERSION} REQUIRED)
target_link_libraries(helibdemo helib)
Compile and run.
cmake .
make
./helibdemo
Obviously there's no output. But it's a first minimal program using HElib.
Good to go and have a look at the examples that were shipped with the library.
Go to the examples folder and compile all examples.
cd ~/HElib/examples/
cmake .
make
Now you'll have compiled examples illustrating BGV and CKKS:
- BGV_binary_arithmetic
- BGV_packed_arithmetic
- BGV_country_db_lookup
- 01_ckks_basics
- 02_ckks_depth
- 03_ckks_data_movement
- 04_ckks_matmul
- 05_ckks_multlowlvl
- 06_ckks_complex
- 07_ckks_serialization
- 08_ckks_deserialization
This example computes a*b+c (one multiplication and one addition) and a+b+c (two additions) for encrypted values of a, b, and c. Note that the security level is total bogus. This example is purely for illustration purposes.
$ time ./bin/BGV_binary_arithmetic
*********************************************************
* Basic Binary Arithmetic Example *
* =============================== *
* *
* This is a sample program for education purposes only. *
* It attempts to demonstrate the use of the API for the *
* binary arithmetic operations that can be performed. *
* *
*********************************************************
Initialising context object...
m = 4095, p = 2, phi(m) = 1728
ord(p) = 12
normBnd = 2.25463
polyNormBnd = 22.5545
factors = [3 5 7 13]
generator 2341 has order (== Z_m^*) of 6
generator 3277 has order (== Z_m^*) of 4
generator 911 has order (== Z_m^*) of 6
r = 1
nslots = 144
hwt = 120
ctxtPrimes = [6,7,8,9,10,11,12,13,14]
specialPrimes = [15,16,17,18,19]
number of bits = 798
security level = 24.2499
Security: 24.2499
Creating secret key...
Number of slots: 144
Pre-encryption data:
a = 16234
b = 39681
c = 37096
a*b+c = 644218450
a+b+c = 93011
popcnt(a) = 10
real 1m2.352s
user 1m2.145s
sys 0m0.204s
The packed arithmetic example is a nice illustration of SIMD (=Single instruction, multiple data).
$ time ./bin/BGV_packed_arithmetic
*********************************************************
* Basic Mathematical Operations Example *
* ===================================== *
* *
* This is a sample program for education purposes only. *
* It attempts to show the various basic mathematical *
* operations that can be performed on both ciphertexts *
* and plaintexts. *
* *
*********************************************************
Initialising context object...
m = 32109, p = 4999, phi(m) = 16560
ord(p) = 690
normBnd = 2.32723
polyNormBnd = 58.2464
factors = [3 7 11 139]
generator 320 has order (== Z_m^*) of 6
generator 3893 has order (== Z_m^*) of 2
generator 14596 has order (== Z_m^*) of 2
T = [ 1 14596 3893 21407 320 14915 25618 11023 6073 20668 9965 27479 16820 31415 10009 27523 20197 2683 24089 9494 9131 23726 2320 19834 ]
r = 1
nslots = 24
hwt = 0
ctxtPrimes = [6,7,8,9,10,11,12,13,14]
specialPrimes = [15,16,17,18,19]
number of bits = 773
security level = 62.4783
Security: 62.4783
Creating secret key...
Generating key-switching matrices...
Number of slots: 24
Initial Plaintext: {"HElibVersion":"2.1.0","content":{"scheme":"BGV","slots":[[0],[1],[2],[3],[4],[5],[6],[7],[8],[9],[10],[11],[12],[13],[14],[15],[16],[17],[18],[19],[20],[21],[22],[23]]},"serializationVersion":"0.0.1","type":"Ptxt"}
Operation: 2(a*a)/(a*a) - 2(a*a)/(a*a) = 0
Decrypted Result: {"HElibVersion":"2.1.0","content":{"scheme":"BGV","slots":[[0],[0],[0],[0],[0],[0],[0],[0],[0],[0],[0],[0],[0],[0],[0],[0],[0],[0],[0],[0],[0],[0],[0],[0]]},"serializationVersion":"0.0.1","type":"Ptxt"}
Plaintext Result: {"HElibVersion":"2.1.0","content":{"scheme":"BGV","slots":[[0],[0],[0],[0],[0],[0],[0],[0],[0],[0],[0],[0],[0],[0],[0],[0],[0],[0],[0],[0],[0],[0],[0],[0]]},"serializationVersion":"0.0.1","type":"Ptxt"}
Operation: Enc{(0 + 1)*1} + (0 + 1)*1
Decrypted Result: {"HElibVersion":"2.1.0","content":{"scheme":"BGV","slots":[[2],[2],[2],[2],[2],[2],[2],[2],[2],[2],[2],[2],[2],[2],[2],[2],[2],[2],[2],[2],[2],[2],[2],[2]]},"serializationVersion":"0.0.1","type":"Ptxt"}
real 0m15.698s
user 0m15.265s
sys 0m0.432s
The next examples demonstrates an encrypted search. Note that we need to point the executable to the countries_dataset.csv in the BGV_country_db_lookup directory.
$ time ./bin/BGV_country_db_lookup db_filename=BGV_country_db_lookup/countries_dataset.csv
*********************************************************
* Privacy Preserving Search Example *
* ================================= *
* *
* This is a sample program for education purposes only. *
* It implements a very simple homomorphic encryption *
* based db search algorithm for demonstration purposes. *
* *
*********************************************************
---Initialising HE Environment ...
Initializing the Context ...
Creating Secret Key ...
Creating Public Key ...
***Security Level: 0 *** Negligible for this example ***
Number of slots: 48
---Initializing the encrypted key,value pair database (47 entries)...
Converting strings to numeric representation into Ptxt objects ...
Encrypting the database...
Initialization Completed - Ready for Queries
--------------------------------------------
Please enter the name of an European Country: Austria
Looking for the Capital of Austria
This may take few minutes ...
Query result: Vienna
timer_TotalQuery: 12.3011 / 1 = 12.3011 [/home/christiane/github/helib-dev/HElib/myexamples/BGV_country_db_lookup/BGV_country_db_lookup.cpp:259]
real 0m20.595s
user 0m12.358s
sys 0m0.008s
Author: Christiane Peters.