Argon2 Java implementation
Switch branches/tags
Nothing to show
Clone or download
Fetching latest commit…
Cannot retrieve the latest commit at this time.

Argon2 Java implementation

This is a pure Java implementation of Argon2. It targets Java 6.

Many parts are just taken from the C code and converted to Java syntax - there shouldn't be any major performance bottlenecks anymore, but speed can't keep up quite with the C implementation.

Fair warning: this code is not well tested and not reviewed. It is not ready for production, use it on your own risk. Same applies for underlying Blake2b implementation.



Red is java, green the reference implementation and blue the optimized implementation with SSE-instructions - run on a i7-7700HQ with 16GB RAM.



You need to install the jar into your local .m2 repository.

Clone and install it:

git clone

cd argon2-java

mvn install


// Read password
char[] password = readPassword();

// Generate salt
String salt = generateRandomSalt();

// Hash password - Builder pattern
String hash = Argon2Factory.create()
            .hash(password, salt);

% java -jar argon2-0.1.jar
usage: argon2 salt [-d | -i | -id] [-e | -r] [-h]   [-k <N> | -m <N>] [-l
      <N>]  [-p <N>]  [-t <N>]
-d       Use Argon2d instead of Argon2i
-e       Output only encoded hash
-h       Print usage
-i       Use Argon2i (this is the default)
-id      Use Argon2id instead of Argon2i
-k <N>   Sets the memory usage of N KiB (default 2^12)
-l <N>   Sets hash output length to N bytes (default 32)
-m <N>   Sets the memory usage of 2^N KiB (default 12)
-p <N>   Sets parallelism to N (default 1)
-r       Output only the raw bytes of the hash
-t <N>   Sets the number of iterations to N (default = 3)
Password is read from stdin


The blake2b Java implementation of @alphazero is used. Because no artifact is available on maven central, I copied the relevant class file into this project - for the sake of simplicity.




  • Verification
  • Encoded result
  • Performance
    • in Block.xorBlock(), the JIT actually already creates vector operations
  • Fix the build
    • Build library without commons-dependency, build executable with
    • maven central
    • add gradle support
  • Add Tests
  • ..