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

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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)

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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)
• Purged all 32-bit support: Windows, Linux, FreeBSD, ARM 32-bit, and PowerPC binaries removed; only 64-bit (x86_64 / ARM64) builds ship
• Note: zen4/zen5 support requires GMP 6.4+ or native hardware for building

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Supported Architectures

The product is 64-bit only. All binaries carry a _64 suffix (for jbigi) or x86_64 (for jcpuid).

Linux (x86_64 64-bit)

none  core2  corei  coreisbr  coreihwl  coreibwl
athlon64  k10  bobcat  jaguar  bulldozer  piledriver  steamroller  excavator
atom  nano  pentium4  zen  zen2  zen3  skylake  silvermont  goldmont

Linux (ARM64 / aarch64)

armv8  armv8.2  cortex-a72  cortex-a76

macOS (x86_64)

none  core2  corei  coreisbr  coreihwl  armv8

Windows (x86_64)

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

FreeBSD (x86_64)

none  atom  nano  k10  pentium4  core2  corei  coreisbr  coreihwl
bobcat  bulldozer  piledriver

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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

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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.

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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.