Awesome

Quick Action

To get started quickly, do the following:

1: Install Ubuntu 12.04 32 bit on a clean box, just to have a common ground (it should come with the default installation but make sure that gcc is installed)

2: Download libScarab-1.0.0.zip, gmp-5.1.1.tar.lz, flint-1.6.tgz, mpir-2.6.0.tar.bz2, mpfr-3.1.1.tar.bz2 from hcrypt.com and the linked web pages

3: Install m4 and lzip

3.1. sudo apt-get install m4

3.2. sudo apt-get install lzip

4: Install gmp

4.1. lzip -d gmp-5.1.1.tar.lz

4.2. tar xf gmp-5.1.1.tar

4.3. cd gmp-5.1.1

4.4. ./configure

4.5. make

4.6. make check #(never ever skip the checks!)

4.7. sudo make install

5: Install mpfr

5.1. tar xjf mpfr-3.1.1.tar.bz2

5.2. cd mpfr-3.1.1

5.3. make

5.4. make check

5.5. sudo make install

6: Install mpir

6.1. tar xjf mpir-2.6.0.tar.bz2

6.2. cd mpir-2.6.0

6.3. ./configure

6.4. make

6.5. make check

6.6. sudo make install

7: Install flint (ok, this is perhaps quite a bit strange)

7.1. tar xf flint-1.6.tgz

7.2. cd flint-1.6

7.3. source flint_env

7.4. make library

7.5. sudo cp libflint.so /usr/local/lib

7.6. sudo cp *.h /usr/local/include

7.7. sudo mkdir -p /usr/local/include/zn_poly/src

7.8. sudo cp zn_poly/include/*.h /usr/local/include/zn_poly/src/

8: Run libscarab test

8.1. mkdir libscarab

8.2. cd libscarab

8.3. unzip ../libScarab-1.0.0.zip

8.4. make

8.5. export LD_LIBRARY_PATH=$LD_LIBRARY_PATH:/usr/local/lib

8.6. ./integer-fhe

ta-daaa!

Introduction

This is an implementation of a fully homomorphic encryption scheme using large integers. The mathematical foundation is based on work by C. Gentry [1] for the initial concept as well as N. Smart and F. Vercauteren [2] for the integer-based approach used in this implementation.

The library presented here is beta software and should not be used for any mission critical applications. No warranty expressed or implied is given.

Installation and usage

Requirements

The following libraries are required for building hcrypt:

GMP: GNU Multiple Precision Arithmetic Library — http://gmplib.org/
FLINT: Fast Library for Number Theory version 1.6 — http://flintlib.org/flint-1.6.tgz
    MPIR: Multiple Precision Integers and Rationals — http://mpir.org/ (required by FLINT)
    MPFR — http://www.mpfr.org/ (required by FLINT)

The library expects the flint headers under in your include directory. Also, copy zn_poly/include/*.h to ./zn_poly/src/ relative to your include path.

Building

The compilation is done using make.

$ make

This builds an integer-fhe executeable in the current directory that runs a test of the library. Usage

You can use the library as demonstrated in test.c. The following methods are exposed: function prototype meaning

fhe_keygen(fhe_pk_t pk, fhe_sk_t sk); Generate a keypair fhe_encrypt(mpz_t c, fhe_pk_t pk, int m); Encrypt a message (0 or 1) fhe_decrypt(mpz_t c, fhe_sk_t sk); Decrypt a cyphertext fhe_recrypt(mpz_t c, fhe_pk_t pk, fhe_sk_t sk); Recrypt a cyphertext (“refreshing” it) fhe_add(mpz_t res, mpz_t a, mpz_t b, fhe_pk_t pk); Add cyphertexts (= XOR) fhe_mul(mpz_t res, mpz_t a, mpz_t b, fhe_pk_t pk); Multiply cyphertexts (= AND) fhe_fulladd(mpz_t sum, mpz_t c_out, mpz_t a, mpz_t b, mpz_t c_in, fhe_pk_t pk); Add with carry in and carry out fhe_halfadd(mpz_t sum, mpz_t c_out, mpz_t a, mpz_t b, fhe_pk_t pk); Add with carry out

References

[1] C. Gentry, A fully homomorphic encryption scheme

[2] N. Smart and F. Vercauteren, Fully Homomorphic Encryption with Relatively Small Key and Ciphertext Sizes

[3] H. Perl, M. Brenner and M. Smith, POSTER: An Implementation of the Fully Homomorphic Smart-Vercauteren Crypto-System

License

Copyright © 2011

THE SOFTWARE IS PROVIDED “AS IS”, WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

SOFTWARE AND SOURCE CODE MAY BE DOWNLOADED AND MODIFIED FOR EDUCATIONAL OR ACADEMIC USE. PATENT PCT/EP2678772B1.