A high-performance, zero-allocation KSUID (Key Sortable Unique Identifier) generator for .NET 8 and .NET 10.

Designed for high-throughput database engines and distributed systems where unique ID generation is on the hot path.

This library is engineered for speed. It uses hardware intrinsics, stackalloc, and a buffered RNG strategy to outperform standard implementations.

• creates crypto-random KSUID strings
• blazing-fast performance
• no additional memory overhead, memory allocation only for string
• thread-safe and lock-free
• targets .net 8, .net 10

• Zero Allocation: Uses string.Create and Span<T> to write directly to the heap, bypassing intermediate string allocations.

• Buffered RNG: Uses a thread-static buffer to amortize the cost of Syscall (randomness) overhead by ~99%.

• Math Intrinsics: Leverages modern .NET Math.DivRem and BinaryPrimitives to optimize the Base62 encoding loop.

$ dotnet add package KsuidDotNet

Create a random KSUID:

string id = Ksuid.NewKsuid();

Console.WriteLine(id); // outputs 29faSiN1gPB6IzM74u6tMfTO02L

Creating a random KSUID string with the prefix cust_:

string id = Ksuid.NewKsuid("cust_");

Console.WriteLine(id); // outputs c_29faSiN1gPB6IzM74u6tMfTO02L

Benchmark results for KsuidDotNet and other KSUID libraries.

BenchmarkDotNet v0.15.6, Windows 11 (10.0.26200.8037)
AMD Ryzen 9 9950X3D 4.30GHz, 1 CPU, 32 logical and 16 physical cores
.NET SDK 10.0.104
  [Host]     : .NET 10.0.4 (10.0.4, 10.0.426.12010), X64 RyuJIT x86-64-v4
  DefaultJob : .NET 10.0.4 (10.0.4, 10.0.426.12010), X64 RyuJIT x86-64-v4

BenchmarkDotNet v0.15.6, macOS Sequoia 15.4 (24E248) [Darwin 24.4.0]
Apple M2 Ultra, 1 CPU, 24 logical and 24 physical cores
.NET SDK 10.0.201
  [Host]     : .NET 10.0.5 (10.0.5, 10.0.526.15411), Arm64 RyuJIT armv8.0-a
  DefaultJob : .NET 10.0.5 (10.0.5, 10.0.526.15411), Arm64 RyuJIT armv8.0-a

This library is open-source software released under the MIT License.