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3

PRNGs are a difficult and hot topic. Some tests can be found here: What tests can I do to ensure my PRNG is working correctly? But they do not tell you (or others) if your PRNG is really secure. A PRNG must be build in a way, that a third party is not able to "calculate" former or upcoming PRNG output based on some random data from the PRNG.

4

You are quite correct. A PRP in counter mode is, in fact, distinguishable from a random sequence if you approach the "birthday bound". We get around this by never generating that much output at once. With a 128 bit block cipher, an output of $2^{40}$ bytes (which is a lot of output) gives us a distinguishing advantage of about $2^{-56}$ (the probability ...

0

As Steth stated before, using system time as seed in cryptographic implementations is terrible idea for any PRNG because this may be simply very predictable. There are better solutions based on noise generated by device drivers in the system (see man urandom) What you want from PRNG in cryptography is to be uniform and unpredictable, so the entropy would be ...

3

How does Web Cryptography API (eg window.crypto.getRandomValues) produce secure PRNG? Like the specification says: Implementations should generate cryptographically random values using well-established cryptographic pseudo-random number generators seeded with high-quality entropy, such as from an operating-system entropy source (e.g., ...

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