JNCryptor is an easy-to-use library for encrypting data with AES. It was ported to Java from the RNCryptor library for iOS.

Follow @JNCryptor for notifications of releases.

You can download binaries, documentation and source from the Releases page. Maven users can copy the following snippet to retrieve the artifacts from Maven Central:

<dependency>
    <groupId>org.cryptonode.jncryptor</groupId>
    <artifactId>jncryptor</artifactId>
    <version>1.1.0</version>
</dependency>

The Javadocs can also be browsed online: JNCryptor Javadocs.

A quick example is shown below:

JNCryptor cryptor = new AES256JNCryptor();
byte[] plaintext = "Hello, World!".getBytes();
String password = "secretsquirrel";

try {
  byte[] ciphertext = cryptor.encryptData(plaintext, password.toCharArray());
} catch (CryptorException e) {
  // Something went wrong
  e.printStackTrace();
}

JNCryptor supports changing the number of PBKDF2 iterations performed by the library. Unfortunately, the number of iterations is not currently encoded in the data format, which means that both sides of the conversation need to know how many iterations have been used.

There are plans afoot to include the ieration count in the data format (hopefully in v4). Until that time, use these feature with caution.

JNCryptor can be used in Android applications, v2.3.3 (Android 10) and above. Download the latest binary release and place the JAR in the libs folder for your project.

Please note that very little Android testing has been completed and some users report compatibility problems with old versions of Android (see the Issues page). If I can find an easy way to do so, I'll start increasing my Android testing and improve the library accordingly.

A proprietary data format is used that stores the IV, salt values (if applicable), ciphertext and HMAC value in a compact fashion. Methods are offered to encrypt data based on either an existing key, or a password. In the latter case, a key is derived from the password using a key derivation function, with 10,000 iterations and a salt valu.e

See the spec documents online.

Keys are derived from the password and the appropriate salt value using the PBKDF2 function with SHA1. A separate key is generated for encrypting the plaintext and computing the HMAC.

The data format supported by this library is v3. Both v1 and v0 have a significant security flaw whereby only the ciphertext was included in the HMAC value. There are no plans to support v1 or v0. v2 was deprecated due to a multi-byte password issue discovered in the objective-c implementation.