import java.security.Key import javax.crypto.Cipher class Rsa { fun encrypt(key: Key, pt: ByteArray): ByteArray { val c = Cipher.getInstance("RSA"); c.init(Cipher.ENCRYPT_MODE, key) return c.doFinal(pt) } fun decrypt(key: Key, ct: ByteArray): ByteArray { val c = Cipher.getInstance("RSA"); c.init(Cipher.DECRYPT_MODE, key) return c.doFinal(ct) } }