KeccakKotlin (2.1.1)

Implements SHA-3 Hash Functions

Digital security for all, everywhere, no matter who they are, or what they believe in.

Introduction

This is a 100% Kotlin Multiplatform implementation of SHA-3. It does not depend on any third-party library.

This is used in KyberKotlin, an ML-KEM implemention of NIST FIPS 203.

Capabilities (NIST FIPS 202)

• SHA3-224 (Byte Stream-able)
• SHA3-256 (Byte Stream-able)
• SHA3-384 (Byte Stream-able)
• SHA3-512 (Byte Stream-able)
• RawSHAKE128 (Extendable, Byte Stream-able)
• RawSHAKE256 (Extendable, Byte Stream-able)
• SHAKE128 (Extendable, Byte Stream-able)
• SHAKE256 (Extendable, Byte Stream-able)

Extended Capabilities / SHA-3 Derived Functions (NIST SP 800-185)

• cSHAKE128 (Extendable, Byte Stream-able)
• cSHAKE256 (Extendable, Byte Stream-able)
• KMAC128 (Byte Stream-able)
• KMAC256 (Byte Stream-able)
• KMACXOF128 (Extendable, Byte Stream-able)
• KMACXOF256 (Extendable, Byte Stream-able)

To Be Supported

Note

These hash functions will be gradually implemented.

• TupleHash128 (Byte Stream-able)
• TupleHash256 (Byte Stream-able)
• TupleHashXOF128 (Extendable, Byte Stream-able)
• TupleHashXOF256 (Extendable, Byte Stream-able)
• ParallelHash128 (Byte Stream-able)
• ParallelHash256 (Byte Stream-able)
• ParallelHashXOF128 (Extendable, Byte Stream-able)
• ParallelHashXOF256 (Extendable, Byte Stream-able)

ParallelHash Functions might need to add coroutine as a dependency.

Tested Platforms

• JVM (Kotlin, Java)

Supported Targets

Target	Arm32	Arm64	X64
JVM (Kotlin & Java)	✅	✅	✅
JS (Node, Bun, & Browser)	✅	✅	✅
Linux	❌ *	❌ **	✅
Windows (Mingw)	❌ *	❌ *	✅
Android	✅	✅	✅
iOS	❌ *	❌ **	❌ **
iOS Simulator	❌ *	❌ **	❌ *

*Note: Some platforms are unavailable/deprecated as targets in Kotlin Multiplatform. Please send your complaints to Jetbrains.

**These targets are currently available, but I have no ability to compile them yet. Once I have more free time, I will set up a publishing server to compile to all targets.

Installation

Maven/Gradle

dependencies {
    implementation("asia.hombre:keccak:2.1.1")
}

Usage

val sha3_224 = SHA3_224().digest()
println(sha3_224.toHexString(HexFormat.UpperCase))
val sha3_256 = SHA3_256().digest()
println(sha3_256.toHexString(HexFormat.UpperCase))
val sha3_384 = SHA3_384().digest()
println(sha3_384.toHexString(HexFormat.UpperCase))
val sha3_512 = SHA3_512().digest()
println(sha3_512.toHexString(HexFormat.UpperCase))

val kmac_128 = KMAC128("key".encodeToByteArray(), 32).digest()
println(kmac_128.toHexString(HexFormat.UpperCase))
val kmac_256 = KMAC256("key".encodeToByteArray(), 64).digest()
println(kmac_256.toHexString(HexFormat.UpperCase))

//Extendable-Output Functions
val rawshake_128 = RawSHAKE128().digest()
println(rawshake_128.toHexString(HexFormat.UpperCase))
val rawshake_256 = RawSHAKE256().digest()
println(rawshake_256.toHexString(HexFormat.UpperCase))
val shake_128 = SHAKE128().digest()
println(shake_128.toHexString(HexFormat.UpperCase))
val shake_256 = SHAKE256().digest()
println(shake_256.toHexString(HexFormat.UpperCase))
val cshake_128 = cSHAKE128().digest()
println(cshake_128.toHexString(HexFormat.UpperCase))
val cshake_256 = cSHAKE256().digest()
println(cshake_256.toHexString(HexFormat.UpperCase))
val kmacxof_128 = KMACXOF128("key".encodeToByteArray()).digest()
println(kmacxof_128.toHexString(HexFormat.UpperCase))
val kmacxof_256 = KMACXOF256("key".encodeToByteArray()).digest()
println(kmacxof_256.toHexString(HexFormat.UpperCase))

//Input Streaming
val shake128_in = SHAKE128.newInputStream()
shake128_in.write("Hello!".encodeToByteArray())
//Output Streaming
val shake128_out = shake128_in.close()
println(shake128_out.nextBytes(1024).toHexString(HexFormat.UpperCase))

View the java example here!

Documentation

• keccak.hombre.asia

References

• Online SHA-3 Keccak Calculator
• NIST CSRC
• XKCP CompactFIPS202
• FIPS 202

License

Copyright 2025 Ron Lauren Hombre

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

       https://www.apache.org/licenses/LICENSE-2.0
       
       and included as LICENSE.txt in this Project.

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.

Although SHA-3 is Public Domain, this implementation is created through Hard Work by its Contributors. Thus, the APACHE LICENSE v2.0 has been chosen.