obfuscxx

Description

Header-only compile-time variables obfuscation library for C++20 and later.

How it works

During compilation, data is encrypted via eXtended Tiny Encryption Algorithm (XTEA). Decryption uses SIMD instructions (AVX/SSE/NEON) at runtime, making static analysis considerably more complicated. Key entropy is based on the preprocessor macro __COUNTER__, the file name(__FILE__), and the line number (__LINE__) where the variable is defined, and the build time (__TIME__) (note: build time is not included when compiling with WDM).

By selecting different encryption levels (Low, Medium, High), you can control the number of encryption rounds. With Low, there are 2 rounds; Medium uses 6; and High adjusts the number of rounds dynamically based on the key entropy, ranging from 6 to 20. This lets you apply lighter encryption to frequently accessed data, and stronger encryption to data that’s used less often.

Decompilation view

The screenshots show only a small portion of the int main() function. In reality, the function can grow to around 250 lines depending on the compiler.

MSVC, LLVM, GCC compilation (int main()) (Level: Low)

Benchmarks

Runtime performance impact

Operation	MSVC	LLVM	GCC
Integer Operations (Low)	3.62 ns	3.31 ns ✓	4.65 ns (1.4x)
Integer Operations (Medium)	10.7 ns (3.0x)	10.3 ns (3.1x) ✓	17.2 ns (3.7x)
Integer Operations (High)	48.3 ns (13.3x)	41.0 ns (12.4x) ✓	56.1 ns (12.1x)
Float Operations (Low)	3.40 ns	3.26 ns ✓	4.22 ns (1.3x)
Float Operations (Medium)	10.8 ns (3.2x)	10.9 ns (3.3x)	16.5 ns (3.9x)
Float Operations (High)	46.7 ns (13.7x)	42.0 ns (12.9x) ✓	56.9 ns (13.5x)
String Operations (Low)	36.8 ns	31.9 ns ✓	43.0 ns (1.3x)
String Operations (Medium)	116 ns (3.2x)	104 ns (3.3x) ✓	174 ns (4.0x)
String Operations (High)	495 ns (13.5x)	429 ns (13.4x) ✓	538 ns (12.5x)
Wide String Operations (Low)	31.8 ns	31.4 ns ✓	47.5 ns (1.5x)
Wide String Operations (Medium)	112 ns (3.5x)	106 ns (3.4x) ✓	172 ns (3.6x)
Wide String Operations (High)	503 ns (15.8x)	417 ns (13.3x) ✓	547 ns (11.5x)
Array Iteration (100 elements, Low)	401 ns	344 ns ✓	436 ns (1.3x)
Array Iteration (100 elements, Medium)	1,136 ns (2.8x)	1,079 ns (3.1x) ✓	1,795 ns (4.1x)
Array Iteration (100 elements, High)	5,114 ns (12.8x)	4,284 ns (12.5x) ✓	5,416 ns (12.4x)
Array Element Access (Low)	3.32 ns	3.21 ns ✓	4.38 ns (1.4x)
Array Element Access (Medium)	11.3 ns (3.4x)	10.2 ns (3.2x) ✓	17.5 ns (4.0x)
Array Element Access (High)	49.8 ns (15.0x)	41.6 ns (13.0x) ✓	56.3 ns (12.9x)

Binary size overhead

Compiler	Without obfuscxx	With obfuscxx	Overhead
MSVC	17.0 KB	18.0 KB	+1,024 bytes (+5.9%)
LLVM	17.5 KB	19.6 KB	+1,560 bytes (+8.7%)
GCC	47.8 KB	52.2 KB	+4,491 bytes (+9.2%)

Test environment:

• CPU: 16 cores @ 2496 MHz
• L1 Data Cache: 48 KiB (x8)
• L1 Instruction Cache: 32 KiB (x8)
• L2 Unified Cache: 512 KiB (x8)
• L3 Unified Cache: 16384 KiB (x1)
• Date: 2025-11-04

Installation

Just add the header file to your project - #include "include/obfuscxx.h"

Examples

Basic:

#include "include/obfuscxx.h"

int main() {
    obfuscxx<int> int_value{ 100 };
    std::cout << int_value.get() << '\n';
    int_value = 50;
    std::cout << int_value.get() << '\n';

    obfuscxx<float> float_value{ 1.5f };
    std::cout << float_value.get() << '\n';

    obfuscxx<int, 4> array{ 1, 2, 3, 4 };
    for (auto val : array) {
        std::cout << val << " ";
    }
    std::cout << '\n';

    obfuscxx str("Hello, World!");
    std::cout << str.to_string() << '\n';

    obfuscxx<int*> pointer{};
    pointer = new int{101};
    std::cout << pointer.get() << " " << *pointer.get() << '\n';
    delete pointer.get();
}

User-Defined literal (Clang/GCC only):

#include "include/obfuscxx.h"

int main() {
    std::cout << "Hello, World!"_obf << '\n';
}

Macros:

#include "include/obfuscxx.h"

int main() {
    std::cout << obfusv(42) << " " << obfusv(3.14159f) << '\n';
    std::cout << obfuss("Hello, World!") << '\n';
}

Building tests and benchmarks

1. Install vcpkg and set VCPKG_ROOT environment variable
2. Fetch baseline: cd $VCPKG_ROOT && git fetch origin 34823ada10080ddca99b60e85f80f55e18a44eea
3. Configure: cmake --preset <compiler> (MSVC/Clang/GCC)
4. Build: cmake --build --preset <compiler> (--config Release/Debug)

Requirements

• C++20 or later
• Compiler with SIMD support (AVX/SSE/NEON)
• CMake 3.15+ (for building tests)
• vcpkg (for dependencies)

Compiler support

• MSVC (+wdm)
• Clang
• GCC

Architecture support

• x86/x86-64 (SSE/AVX)
• ARM (NEON)