i2pplus

JBIGI Native Libraries

Note: For the latest information, see:

history.txt for changelog entries

core/c/jbigi/README.md for build instructions

NativeBigInteger.java and CPUID.java for technical details

What is JBIGI?

JBIGI provides native JNI bindings for the GNU Multiple Precision Arithmetic Library (GMP) to accelerate cryptographic operations in I2P, including:

Modular exponentiation (modPow)
Constant-time modular exponentiation (modPowCT) - resistant to timing attacks
Modular multiplicative inverse (modInverse)

Current Version (March 2026)

Component	Version
GMP	6.3.0
JBIGI	4

The JBIGI version can be queried at runtime via nativeJbigiVersion().

New in This Release

Added libjbigi-linux-none_64.so - Generic 64-bit Linux build (GMP 6.3.0)
Added jbigi-windows-none_64.dll - Generic 64-bit Windows build (GMP 6.3.0)
Removed deprecated PowerPC Linux binary
Note: zen4/zen5 support requires GMP 6.4+ or native hardware for building

Supported Architectures

Linux (x86 32-bit)

none  pentium  pentium2  pentium3  pentium4  pentiumm  pentiummmx
k6  k62  athlon  geode  viac3  viac32

Linux (x86_64 64-bit)

none_64  core2  corei  coreisbr  coreihwl  coreibwl
athlon64  k10  bobcat  jaguar  bulldozer  piledriver  steamroller  excavator
atom  nano  pentium4  zen  zen2  skylake  silvermont  goldmont

Linux (ARM)

armv5  armv6  armv7  armv7a  armcortex8  armcortex9  armcortex15
armv8  armv8_64  aarch64

macOS

core2  corei  coreisbr  coreihwl  coreibwl

Windows

Same architectures as Linux (compiled via MinGW cross-compilation)

FreeBSD

Same architectures as Linux

Build History

2026 - March

Upgraded to GMP 6.3.0
JBIGI version 4: Added version reporting functions (nativeJbigiVersion, nativeGMP*Version)
Added nativeModPowCT (constant-time modular exponentiation)
Added nativeModInverse
Code cleanup: removed dead code, fixed convert_mp2j() off-by-one error
Added ARMv8/aarch64 support

2016 - April

Upgraded to GMP 6.0.0a
Removed: NetBSD, kFreeBSD, Solaris, OpenBSD
Added: coreihwl, coreisbr, bulldozer, steamroller, cortex-a9, cortex-a15

2011 - May/June

jcpuid: Updated for -fPIC compatibility
jbigi:
- Removed k63 (falls back to k62)
- 32-bit: GMP 4.3.2
- 64-bit: GMP 5.0.2
- Added MinGW cross-compiled Windows 64-bit binaries

2006 - February

Added libjbigi-linux-viac3.so
Created jbigi-win-athlon64.dll

2005 - December

Updated libjcpuid-x86-linux.so to pure C (removed libg++.so.5 dependency)

2005 - September

Added libjbigi-linux-athlon64.so

2004 - August

Initial release with GMP 4.1.3
Platforms: Linux, Windows (MinGW), FreeBSD 4.8

Rebuilding from Source

To rebuild jbigi for your specific architecture:

# Linux 64-bit
cd core/c/jbigi
./build-linux64.sh -a

# Windows 64-bit (cross-compile with MinGW)
./build-win64.sh -a

# ARM64 (cross-compile with aarch64-linux-gnu-gcc)
./build-arm64.sh -a

For more options, see core/c/jbigi/README.md.

File Naming Convention

The library naming follows {lib}jbigi-{OS}-{CPU}.{ext}:

OS	Prefix	Extension
Linux	libjbigi	.so
FreeBSD	libjbigi	.so
macOS	libjbigi	.jnilib
Windows	jbigi	.dll

The CPUID library at runtime selects the optimal binary for your CPU based on detected features.