Getting Started

Prerequisites

Make sure that you use Kotlin 2.3.0+. Using an earlier Kotlin version could still work, but not tested. The library is published to Maven Central, so make sure that it’s added to repositories.

Add dependencies

Add cryptography-core and a provider to your project. For most users, the optimal provider is the right choice — it automatically selects the best provider for each target platform.

kotlin {
    sourceSets {
        commonMain.dependencies {
            implementation("dev.whyoleg.cryptography:cryptography-core:0.6.0")
            implementation("dev.whyoleg.cryptography:cryptography-provider-optimal:0.6.0")
        }
    }
}

If the optimal provider doesn’t cover your needs (e.g., you need BouncyCastle or a specific OpenSSL linking option), see Choosing a Provider.

For alternative ways to manage dependencies, such as BOM or Gradle version catalog, see Dependency Management.

Your first hash

// get a hasher
val hasher = CryptographyProvider.Default.get(SHA512).hasher()
// hash a message
val digest = hasher.hash("Kotlin is Awesome".encodeToByteArray())

Learn more about Hashing.

Sign a message

// get an algorithm
val ecdsa = CryptographyProvider.Default.get(ECDSA)
// generate a key pair
val keyPair = ecdsa.keyPairGenerator(EC.Curve.P256).generateKey()
// sign a message via private key
val signature = keyPair.privateKey
    .signatureGenerator(digest = SHA256)
    .generateSignature("message".encodeToByteArray())
// verify a signature via public key
val isValid = keyPair.publicKey
    .signatureVerifier(digest = SHA256)
    .tryVerifySignature("message".encodeToByteArray(), signature)

Learn more about Digital Signatures.

Encrypt data

// get an algorithm
val aesGcm = CryptographyProvider.Default.get(AES.GCM)
// generate a key
val key = aesGcm.keyGenerator().generateKey()
// use cipher to encrypt and decrypt data
val cipher = key.cipher()
val ciphertext = cipher.encrypt(plaintext = "secretdata".encodeToByteArray())
val decrypted = cipher.decrypt(ciphertext = ciphertext)

Learn more about AEAD.

---

Want to understand how these pieces connect? See the Primitives overview.