Version 2.0.0

.gitignore

@@ -1,15 +1,13 @@
-scutil.*
+# files related to build
 build/
+.cache/
+
+# do not track compiled documentation files
 doc/
-/TAGS
-/GPATH
-/GRTAGS
-/GTAGS
-/.projectile
+
+# build files for examples
 examples/build/
-examples/libscl.*
+
+# misc IDE stuff
 secure-computation-library.*
-/.cache/
-/compile_commands.json
-/lib/
-/install/
+compile_commands.json

CMakeLists.txt

@@ -16,13 +16,20 @@
 
 cmake_minimum_required( VERSION 3.14 )
 
-project( scl VERSION 1.1.1 DESCRIPTION "Secure Computation Library" )
+project( scl VERSION 2.0.0 DESCRIPTION "Secure Computation Library" )
 
 if(NOT CMAKE_BUILD_TYPE)
   set(CMAKE_BUILD_TYPE Release)
 endif()
 
+option(WITH_EC "Include support for elliptic curves (requires GMP)" ON)
+
 message(STATUS "CMAKE_BUILD_TYPE=" ${CMAKE_BUILD_TYPE})
+message(STATUS "WITH_EC=" ${WITH_EC})
+
+if(WITH_EC MATCHES ON)
+  find_library(GMP gmp libgmp REQUIRED)
+endif()
 
 set(CMAKE_MODULE_PATH ${CMAKE_MODULE_PATH} "${CMAKE_SOURCE_DIR}")
 set(CMAKE_CXX_FLAGS  "${CMAKE_CXX_FLAGS} -march=native -Wall -Wextra -pedantic -Werror -std=gnu++17")
@@ -44,6 +51,13 @@ set(SCL_SOURCE_FILES
   src/scl/net/discovery/server.cc
   src/scl/net/discovery/client.cc)
 
+if(WITH_EC MATCHES ON)
+  set(SCL_SOURCE_FILES ${SCL_SOURCE_FILES}
+    src/scl/math/secp256k1_field.cc
+    src/scl/math/secp256k1_curve.cc
+    src/scl/math/number.cc)
+endif()
+
 set(SCL_HEADERS "${CMAKE_SOURCE_DIR}/include")
 
 include_directories(${SCL_HEADERS})
@@ -65,7 +79,7 @@ if(CMAKE_BUILD_TYPE MATCHES "Release")
     FILES_MATCHING PATTERN "*.h")
 
 endif()
-  
+
 if(CMAKE_BUILD_TYPE MATCHES "Debug")
 
   set(SCL_TEST_SOURCE_FILES
@@ -97,29 +111,40 @@ if(CMAKE_BUILD_TYPE MATCHES "Debug")
 
     test/scl/p/test_simple.cc)
 
-    set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -O0")
-    find_package(Catch2 REQUIRED)
-    include(CTest)
-    include(Catch)
-    include(${CMAKE_SOURCE_DIR}/cmake/CodeCoverage.cmake)
-
-    # Tests that check bounds for reading/writing are sped up considerably by
-    # lowering said bounds.
-    add_compile_definitions(MAX_VEC_READ_SIZE=1024)
-    add_compile_definitions(MAX_MAT_READ_SIZE=1024)
-    add_compile_definitions(SCL_TEST_DATA_DIR="${CMAKE_SOURCE_DIR}/test/data/")
-
-    add_executable(scl_test ${SCL_SOURCE_FILES} ${SCL_TEST_SOURCE_FILES})
-    target_link_libraries(scl_test Catch2::Catch2 pthread)
-    catch_discover_tests(scl_test)
-
-    append_coverage_compiler_flags()
-
-    # Tell lcov to ignore system STL headers in order to make the coverage
-    # output more precise.
-    setup_target_for_coverage_lcov(
-      NAME coverage
-      EXECUTABLE scl_test
-      EXCLUDE "/usr/include/*" "test/*" "/usr/lib/*" "/usr/local/*")
+  if(WITH_EC MATCHES ON)
+    set(SCL_TEST_SOURCE_FILES ${SCL_TEST_SOURCE_FILES}
+      test/scl/math/test_secp256k1.cc
+      test/scl/math/test_number.cc)
+    add_compile_definitions(SCL_ENABLE_EC_TESTS)
+  endif()
+
+  set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -O0")
+  find_package(Catch2 REQUIRED)
+  include(CTest)
+  include(Catch)
+  include(${CMAKE_SOURCE_DIR}/cmake/CodeCoverage.cmake)
+
+  # Lower the max size of Vec/Mat reads to speed up tests
+  add_compile_definitions(MAX_VEC_READ_SIZE=1024)
+  add_compile_definitions(MAX_MAT_READ_SIZE=1024)
+  add_compile_definitions(SCL_TEST_DATA_DIR="${CMAKE_SOURCE_DIR}/test/data/")
+
+  add_executable(scl_test ${SCL_SOURCE_FILES} ${SCL_TEST_SOURCE_FILES})
+  target_link_libraries(scl_test Catch2::Catch2 pthread)
+
+  if(WITH_EC MATCHES ON)
+    target_link_libraries(scl_test ${GMP})
+  endif()
+
+  catch_discover_tests(scl_test)
+
+  append_coverage_compiler_flags()
+
+  # Tell lcov to ignore system STL headers in order to make the coverage
+  # output more precise.
+  setup_target_for_coverage_lcov(
+    NAME coverage
+    EXECUTABLE scl_test
+    EXCLUDE "/usr/include/*" "test/*" "/usr/lib/*" "/usr/local/*")
 
 endif()

DoxyConf

@@ -100,7 +100,8 @@ WARN_LOGFILE           =
 INPUT                  = ./include \
                          ./include/scl \
                          ./include/scl/math \
-                         ./include/scl/math/z2k \
+                         ./include/scl/math/fields \
+			 ./include/scl/math/curves \
                          ./include/scl/ss \
                          ./include/scl/net \
                          ./include/scl/net/discovery \
@@ -111,7 +112,7 @@ RECURSIVE              = NO
 EXCLUDE                =
 EXCLUDE_SYMLINKS       = NO
 EXCLUDE_PATTERNS       =
-EXCLUDE_SYMBOLS        = _SCL_*
+EXCLUDE_SYMBOLS        = SCL_*
 EXAMPLE_PATH           =
 EXAMPLE_PATTERNS       = *
 EXAMPLE_RECURSIVE      = NO
@@ -133,7 +134,6 @@ VERBATIM_HEADERS       = YES
 CLANG_ASSISTED_PARSING = NO
 CLANG_OPTIONS          =
 ALPHABETICAL_INDEX     = YES
-COLS_IN_ALPHA_INDEX    = 5
 IGNORE_PREFIX          =
 GENERATE_HTML          = YES
 HTML_OUTPUT            = html

README.md

@@ -1,15 +1,16 @@
 # SCL — Secure Computation Library
 
-SCL is a utilities library for prototyping Secure Multiparty Computation (MPC
-for short) protocols. The focus of SCL is usability, both in terms of the
-interfaces provided, but also the build process (SCL has no external
-dependencies, for example). SCL moreover attempts to provide functionality that
-abstracts away all the annoying "boilerplate" code that is needed for
-implementing a new and exciting MPC protocol, such as implementing a finite
-field, getting networking to work, or instantiating a PRG or hash function.
-
-Hopefully, by using SCL, researches (and hobbyists) will find it a lot easier,
-and quicker!, to implement MPC protocols.
+SCL is a utilities library for prototyping Secure Multiparty Computation (_MPC_
+for short) protocols. The focus of SCL is usability, not necessarily speed. What
+this means is that SCL strives to provide an intuitive, easy to use and
+understand and well documented interface that helps the programmer prototype an
+MPC protocol faster (and nicer) than if they had to write everything themselves.
+
+SCL provides high level interfaces and functionality for working with
+* Secret sharing, additive and Shamir.
+* Finite fields.
+* Networking.
+* Primitives, such as hash functions and PRGs.
 
 ### Disclaimer
 
@@ -20,13 +21,11 @@ This program is distributed in the hope that it will be useful, but WITHOUT ANY
 WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A
 PARTICULAR PURPOSE.
 
-
 # Building SCL
 
-SCL has no external dependencies, except if you want to build the unittests. In
-that case, [catch2](https://github.com/catchorg/Catch2/tree/v2.x) is required as
-that's the framework used for testing, as well as ~lcov~ for generating test
-coverage.
+SCL uses [gmp](https://gmplib.org/) for working with Elliptic Curves, and
+[catch2](https://github.com/catchorg/Catch2/tree/v2.x) for testing and `lcov`
+for test coverage.
 
 The CMake file recongnizes two different build types: `Debug` and `Release`, the
 latter being the default. In either case, building is straight forward and can
@@ -47,6 +46,10 @@ after the build command. By default, headers are install in `usr/local/include`
 and the shared library in `/usr/local/lib`. This location can be controlled by
 setting the `CMAKE_INSTALL_PREFIX` accordingly.
 
+Support for Elliptic Curves can be disabled (and thus remove the need to have
+gmp installed) by passing `-DWITH_EC=OFF` to cmake.
+
+
 # Using SCL
 
 To use SCL, link `libscl.so` when building your program and include the

RELEASE.txt

@@ -1,3 +1,13 @@
+2.0: Elliptic curves and finite field refactoring
+- Make it simpler to define new finite fields
+- Include optional (but enabled by default) support for elliptic curves
+  - Implement secp256k1
+- Include optional (but enabled by default) support for multi-precision integers
+- Significantly increase test coverage
+- Make header guards standard compliant
+- Rename FF<Bits> to Fp<Bits>.
+- Move class FF into scl namespace.
+
 1.1: Refactoring of finite field internals
 - Finite field operations are now defined by individual specializations of
   templated functions

examples/02_finite_fields.cc

@@ -33,7 +33,7 @@ int main() {
    * which returns the actual size of a field element (so 61 bits in the below
    * case).
    */
-  using FF = scl::FF<32>;
+  using Fp = scl::Fp<32>;
 
   /* FF supports constructing an element from an int constant. The value input
    * is interpreted "modulo p" where p is the prime. This makes it possible to
@@ -42,9 +42,9 @@ int main() {
    * The default construtor of FF can be used to construct an element equal to
    * 0.
    */
-  auto a = FF(1);
-  auto b = FF(1234);
-  auto c = FF(555);
+  auto a = Fp(1);
+  auto b = Fp(1234);
+  auto c = Fp(555);
 
   /* FF supports all operations required for a field, so addition, subtraction,
    * multiplication and "division". Division is defined as multiplication by the
@@ -71,16 +71,16 @@ int main() {
 
   /* Using a PRG (see the PRG example), we can generate random field elements.
    */
-  std::cout << FF::Random(prg) << "\n";
-  std::cout << FF::Random(prg) << "\n";
-  std::cout << FF::Random(prg) << "\n";
+  std::cout << Fp::Random(prg) << "\n";
+  std::cout << Fp::Random(prg) << "\n";
+  std::cout << Fp::Random(prg) << "\n";
 
   /* Serialization is also supported.
    */
-  unsigned char buffer[FF::ByteSize()];
+  unsigned char buffer[Fp::ByteSize()];
 
   a.Write(buffer);
-  auto a_ = FF::Read(buffer);
+  auto a_ = Fp::Read(buffer);
 
   std::cout << (a_ == a) << "\n";
 }

examples/03_secret_sharing.cc

@@ -25,13 +25,13 @@
 #include <stdexcept>
 
 int main() {
-  using FF = scl::FF<32>;
-  using Vec = scl::Vec<FF>;
+  using Fp = scl::Fp<32>;
+  using Vec = scl::Vec<Fp>;
   scl::PRG prg;
 
   /* We can easily create an additive secret sharing of some secret value:
    */
-  FF secret(12345);
+  Fp secret(12345);
   Vec shares = scl::CreateAdditiveShares(secret, 5, prg);
 
   std::cout << "additive shares:\n" << shares << "\n";
@@ -59,7 +59,7 @@ int main() {
 
   /* If we introduce an error, then reconstruction fails
    */
-  shamir_shares[2] = FF(123);
+  shamir_shares[2] = Fp(123);
   try {
     std::cout << scl::ReconstructShamir(shamir_shares, 1) << "\n";
   } catch (std::logic_error& e) {
@@ -78,7 +78,7 @@ int main() {
   /* first we need the alphas that were used when generating the shares. By
    * default these are just the field elements 1 through 4.
    */
-  Vec alphas = {FF(1), FF(2), FF(3), FF(4)};
+  Vec alphas = {Fp(1), Fp(2), Fp(3), Fp(4)};
   auto pe = scl::ReconstructShamirRobust(shamir_shares, alphas, 1);
 
   /* pe is a pair of polynomials. The first is the original polynomial used for
@@ -87,16 +87,16 @@ int main() {
    *
    * The secret is embedded in the constant term.
    */
-  std::cout << pe[0].Evaluate(FF(0)) << "\n";
+  std::cout << pe[0].Evaluate(Fp(0)) << "\n";
 
   /* This will be 0, indicating that the share corresponding to party 3 had an
    * error.
    */
-  std::cout << pe[1].Evaluate(FF(3)) << "\n";
+  std::cout << pe[1].Evaluate(Fp(3)) << "\n";
 
   /* Lastly, if there's too many errors, then correction is not possible
    */
-  shamir_shares[1] = FF(22);
+  shamir_shares[1] = Fp(22);
   try {
     scl::ReconstructShamirRobust(shamir_shares, 1);
   } catch (std::logic_error& e) {

examples/04_networking.cc

@@ -22,6 +22,8 @@
 
 #include <iostream>
 
+#include "scl/net/tcp_channel.h"
+
 scl::NetworkConfig RunServer(int n) {
   scl::DiscoveryServer server(n);
   scl::Party party{0, "127.0.0.1", 5000};
@@ -63,7 +65,7 @@ int main(int argc, char** argv) {
    * around.
    */
 
-  auto network = scl::Network::Create(config);
+  auto network = scl::Network::Create<scl::TcpChannel>(config);
 
   for (std::size_t i = 0; i < 3; ++i) {
     // similar to the TCP channel example, send our ID to everyone:

examples/CMakeLists.txt

@@ -20,22 +20,25 @@ project( scl_examples VERSION 1.0 DESCRIPTION "SCL example programs" )
 
 set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -march=native -O2 -std=gnu++17" )
 
+find_library(GMP gmp libgmp REQUIRED)
+find_library(SCL scl libscl REQUIRED)
+
 ## primitives
 set( primitives "01_primitives" )
 add_executable( "${primitives}" "${primitives}.cc" )
-target_link_libraries( "${primitives}" scl pthread )
+target_link_libraries( "${primitives}" "${SCL}" "${GMP}" pthread )
 
 ## finite fields
 set( finite_fields "02_finite_fields" )
 add_executable( "${finite_fields}" "${finite_fields}.cc" )
-target_link_libraries( "${finite_fields}" scl pthread )
+target_link_libraries( "${finite_fields}" "${SCL}" "${GMP}" pthread )
 
 ## secret sharing
 set( secret_sharing "03_secret_sharing" )
 add_executable( "${secret_sharing}" "${secret_sharing}.cc" )
-target_link_libraries( "${secret_sharing}" scl pthread )
+target_link_libraries( "${secret_sharing}" "${SCL}" "${GMP}" pthread )
 
 ## simple networking
 set( networking "04_networking" )
 add_executable( "${networking}" "${networking}.cc" )
-target_link_libraries( "${networking}" scl pthread )
+target_link_libraries( "${networking}" "${SCL}" "${GMP}" pthread )

include/scl/hash.h

@@ -18,8 +18,8 @@
  * along with this program.  If not, see <https://www.gnu.org/licenses/>.
  */
 
-#ifndef _SCL_HASH_H
-#define _SCL_HASH_H
+#ifndef SCL_HASH_H
+#define SCL_HASH_H
 
 #include <array>
 #include <cstdint>
@@ -214,4 +214,4 @@ std::string DigestToString(const D &digest) {
 
 }  // namespace scl
 
-#endif  // _SCL_HASH_H
+#endif  // SCL_HASH_H