Java Fortuna PRNG clean room implementation. This implementation is JCA compatible. This allow to use Fortuna as secure random number generator for all Java applications.
Add Maven dependency
<dependency>
<groupId>dev.prokop.crypto</groupId>
<artifactId>fortune-teller</artifactId>
<version>1.0.1</version>
</dependency>Register JCA provider.
Security.addProvider(new FortunaJcaProvider());Request SecureRandom instance and generate some random numbers.
final SecureRandom fortuna = SecureRandom.getInstance("Fortuna");
fortuna.generateSeed(22); // generates 22 random bytes
final byte[] bytes = new byte[1024];
fortuna.nextBytes(bytes); // fills byte array with 1 KiB of random dataThat's it.
Don't trust what you read here, please test it on your system before use. Your mileage can vary. You have been warned.
$ wget https://repo1.maven.org/maven2/dev/prokop/crypto/fortune-teller/1.0.1/fortune-teller-1.0.1.jar
$ java -cp fortune-teller-1.0.1.jar dev.prokop.crypto.fortuna.DieHarder | dieharder -g200 -a
#=============================================================================#
# dieharder version 3.31.1 Copyright 2003 Robert G. Brown #
#=============================================================================#
rng_name |rands/second| Seed |
stdin_input_raw| 4.12e+06 |3855428203|
#=============================================================================#
test_name |ntup| tsamples |psamples| p-value |Assessment
#=============================================================================#
diehard_birthdays| 0| 100| 100|0.92706545| PASSED
diehard_operm5| 0| 1000000| 100|0.89760746| PASSED
diehard_rank_32x32| 0| 40000| 100|0.28649369| PASSED
diehard_rank_6x8| 0| 100000| 100|0.83184980| PASSED
diehard_bitstream| 0| 2097152| 100|0.67206395| PASSED
diehard_opso| 0| 2097152| 100|0.58135346| PASSED
...Try to generate some images:
java -cp fortune-teller-1.0.1.jar dev.prokop.crypto.fortuna.DieHarder | rawtoppm -rgb 256 256 > pixmap
cat pixmap | pnmtopng > random$(date +%Y%m%d%H%M%S).png