msh086 / bgv-boot-for-large-p

The code for https://eprint.iacr.org/2024/115.

Building

First clone HElib with git.

git clone [email protected]:homenc/HElib.git
cd HElib
git checkout 3e337a6

Then, copy the bgvboot-final.patch file into HElib/ and apply the changes by

git apply bgvboot-final.patch

You need to replace the path your_path_to_main_dir in HElib/src/extractDigits.cpp to the directory path of fatboot.cpp.

Then build and install HElib following the instructions in INSTALL.md, some dependencies like NTL and gmp may be needed. Remember to build in either Release or RelWithDebInfo mode.

Finally, switch to the directory of fatboot.cpp and build the test program by

cmake -S . -B build
cmake --build build

If CMake cannot final HElib, you may need to change the helib_DIR variable in CMakeLists.txt to the correct install path of HElib.

Running

If the building is successful, it will produce a binary file build/fatboot. Running build/fatboot -h will display the following help message

Usage: build/fatboot [i=<arg>] [h=<arg>] [t=<arg>] [newbts=<arg>] [newks=<arg>] [thick=<arg>] [repeat=<arg>]
  i      index of the chosen parameter set [ default=0 ]
  h      hwt of encapsulated key [ default=0 ]
  t      parameter t used in new bts [ default=0 ]
  newbts if new bts is used [ default=0 ]
  newks  if new ks is used [ default=1 ]
  thick  if thick bts is used [ default=0 ]
  repeat number of tests [ default=5 ]

• Five parameter sets are available (given in Table 3 of the paper with ID I, II, III, IV and V). By setting the argument i to an integer in 0 to 4, the corresponding parameter set is chosen.
• The Hamming weight of the encapsulated secret key needs to be assigned through the argument h. Again, please refer to Table 3 for the values of h with 80 or 128 bits of security.
• Argument t controls the $t$ in our paper, i.e., $t=v_p(\Delta)$. Setting t=0 tells the program to decide a positive $t$ that is as small as possible (type-A parameters), while setting t=-1 uses $\Delta=\Delta_0$, i.e., $t=0$ (type-B parameters). Setting t to any positive integer will also set $t$ to the same value.
• Set newbts=1 if you want to test our optimized digit removal. Set newbts=0 to test the native implementation of HElib.
• Set thick=1 to test general bootstrapping. Set thick=0 to test thin bootstrapping.
• Argument repeat indicates the number of tests to run. The performance data will be averaged over these tests.