secure-random

Java 9 (JSR 379) introduces the NIST DRBG's as specified in JEP 273 . However, the NIST document SP 800-90Ar1 (NIST Special Publication 800-90A Revision 1: Recommendation for Random Number Generation Using Deterministic Random Bit Generators) specifies a total of tree mechanisms: Implement the three DRBG mechanisms (Hash_DRBG, HMAC_DRBG, CTR_DRBG) in 800-90Ar1 (on all platforms). However, although you might expect that we would now have three methods to create such secure random algorithms: SecureRandom.getInstance("Hash_DRBG") SecureRandom.getInstance("HMAC_DRBG") SecureRandom.getInstance(

Currently, I'm looking for a way to increase the quality of randomness in my Android application (a card game). Previously, it was estimated that for my situation (52! permutation) at least 226 bits of entropy (226 random bits) are needed.. I'm planning to use this byte[] as a seed for SecureRandom : SecureRandom random = new SecureRandom(); random.setSeed(/* insert seed here, byte[] */) The question is -- Where can I reliably get random bits in this amount (at least 226 bits) on Android , preferably without requiring any permissions and without internet. Also, it should work regardless of

Users can purchase a "Pro" version of my app. When they do, I store and verify their purchase as follows. Combine the user's UUID and another unique string. The resulting string is then encrypted using a static seed. I do this using SecureRandom.getInstance("SHA1PRNG", "Crypto") - This is the problem! The resulting encrypted string is then the "unlock code". Therefore, I always know the expected unique unlock code value for the user. When the user purchases "Pro", I store the "unlock code" in the database. I check to see whether the user has "Pro" by seeing if the stored "unlock code" in the

How do I generate a random number between 0 and n ? VonC Use rand(range) From Ruby Random Numbers : If you needed a random integer to simulate a roll of a six-sided die, you'd use: 1 + rand(6) . A roll in craps could be simulated with 2 + rand(6) + rand(6) . Finally, if you just need a random float, just call rand with no arguments. As Marc-André Lafortune mentions in his answer below (go upvote it) , Ruby 1.9.2 has its own Random class (that Marc-André himself helped to debug , hence the 1.9.2 target for that feature). For instance, in this game where you need to guess 10 numbers , you can