Package gnu.crypto.prng

Class FortunaStandalone

java.lang.Object
gnu.crypto.prng.BasePRNGStandalone
gnu.crypto.prng.FortunaStandalone
All Implemented Interfaces:
IRandomStandalone, Serializable, Cloneable
Direct Known Subclasses:
AsyncFortunaStandalone
public class FortunaStandalone
extends BasePRNGStandalone
implements Serializable
The Fortuna continuously-seeded pseudo-random number generator. This generator is composed of two major pieces: the entropy accumulator and the generator function. The former takes in random bits and incorporates them into the generator's state. The latter takes this base entropy and generates pseudo-random bits from it.

There are some things users of this class must be aware of:

Adding Random Data
This class does not do any polling of random sources, but rather provides an interface for adding random events. Applications that use this code must provide this mechanism. We use this design because an application writer who knows the system he is targeting is in a better position to judge what random data is available.
Storing the Seed
This class implements Serializable in such a way that it writes a 64 byte seed to the stream, and reads it back again when being deserialized. This is the extent of seed file management, however, and those using this class are encouraged to think deeply about when, how often, and where to store the seed.

References:

  • Niels Ferguson and Bruce Schneier, Practical Cryptography, pp. 155--184. Wiley Publishing, Indianapolis. (2003 Niels Ferguson and Bruce Schneier). ISBN 0-471-22357-3.
Modified by jrandom for I2P to use a standalone gnu-crypto SHA256, Cryptix's AES, to strip out some unnecessary dependencies and increase the buffer size. Renamed from Fortuna to FortunaStandalone so it doesn't conflict with the gnu-crypto implementation, which has been imported into GNU/classpath NOTE: As of 0.8.8, uses the java.security.MessageDigest instead of GNU Sha256Standalone
See Also:
Serialized Form