KpqC 0.1.1

KpqC

KpqC provides safe, synchronous .NET APIs for AIMer, HAETAE, NTRU+, and SMAUG-T.

Runtime support

• .NET 8 or newer
• Windows x64
• Linux x64 or Arm64
• macOS x64 or Apple silicon

Install

dotnet add package KpqC

Available schemes

Importing an algorithm family keeps the entry point focused:

using KpqC;

ReadOnlySpan<byte> payload = "release-manifest:v3"u8;
using KeyPair keys = Aimer.Aimer128F.GenerateKeyPair();
byte[] proof = Aimer.Aimer128F.Sign(payload, keys.SecretKey);

if (!Aimer.Aimer128F.Verify(payload, proof, keys.PublicKey))
{
    throw new InvalidOperationException("Signature verification failed");
}

Signature contexts

AIMer and HAETAE accept an optional context. A context separates signatures created for different application purposes and may contain up to 255 bytes.

using KpqC;

ReadOnlySpan<byte> payload = "account=42"u8;
ReadOnlySpan<byte> context = "audit-record"u8;
using KeyPair keys = Haetae.Haetae3.GenerateKeyPair();

byte[] signature = Haetae.Haetae3.Sign(payload, keys.SecretKey, context);
bool valid = Haetae.Haetae3.Verify(
    payload,
    signature,
    keys.PublicKey,
    context);

Console.WriteLine(valid); // True

Verification fails when the supplied context does not match the one used for signing.

Key encapsulation

A KEM creates a shared secret for a sender and a recipient. The public key may be distributed; the secret key and resulting shared secret must remain private.

using KpqC;

using KeyPair recipient = SmaugT.SmaugT192.GenerateKeyPair();
using EncapsulatedSecret outbound =
    SmaugT.SmaugT192.Encapsulate(recipient.PublicKey);
// Send outbound.Ciphertext to the recipient.

byte[] inboundSecret = SmaugT.SmaugT192.Decapsulate(
    outbound.Ciphertext,
    recipient.SecretKey);

Console.WriteLine(
    inboundSecret.AsSpan().SequenceEqual(outbound.SharedSecret)); // True

The caller is responsible for clearing the array returned by Decapsulate when it is no longer needed.

Imports

Each family has a dedicated static class:

using KpqC;

SignatureAlgorithm signer = Aimer.Aimer256S;
SignatureAlgorithm anotherSigner = Haetae.Haetae5;
KeyEncapsulationAlgorithm keyExchange = NtruPlus.NtruPlus1152;
KeyEncapsulationAlgorithm anotherKeyExchange = SmaugT.Timer;

All named algorithms are also available from Algorithms:

using KpqC;

SignatureAlgorithm signer = Algorithms.Aimer192F;
KeyEncapsulationAlgorithm keyExchange = Algorithms.NtruPlus864;

Data and failures

Inputs are ReadOnlySpan<byte> values and outputs are byte[] values. Each algorithm exposes an Id and a Sizes value.

Parameter sizes

All sizes are in bytes.

Signatures

Key encapsulation

Methods reject values of the wrong size. Signature verification returns false for an invalid signature. NTRU+ rejects an invalid ciphertext. SMAUG-T performs implicit rejection and returns a replacement secret instead; that value will not equal the sender's shared secret.

Distribution

The published package includes the managed .NET assembly and native libraries for each supported runtime identifier. It has no runtime package dependencies.

KeyPair and EncapsulatedSecret implement IDisposable. Their secret-key and shared-secret arrays are wiped on disposal on a best-effort basis.

Building from source

A C11 compiler, CMake 3.20 or newer, and the .NET 8 SDK are required. Build and stage the native library for the current platform before running the managed tests or packing:

./scripts/build-native.sh osx-arm64
dotnet test tests/KpqC.Tests/KpqC.Tests.csproj -c Release -r osx-arm64
dotnet pack src/KpqC/KpqC.csproj -c Release -p:AllowPartialRuntimePack=true

Use the matching RID on other supported platforms. Windows builds can use scripts/build-native.ps1. A release package requires all supported RID assets; AllowPartialRuntimePack is intended only for local validation.

Security

The native cores are compiled from the upstream algorithm implementations. This package has not received an independent security audit and does not provide a constant-time execution guarantee. Assess those constraints before using it with sensitive production keys.

Third-party licenses and attributions are listed in THIRD_PARTY_NOTICES.md.