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1

Short answer: Yes. If the PRNG is cryptographically secure and it generates a certain chunk of bits at a time, then any subset of the chunk generated by the PRNG should be just as "random" as the full chunk, but this would depend on the specific implementation of the CSPRNG. For certainty, I would refer to the full documentation of the API you're using. If ...


2

Yes. Although the bit values are not identical per se (even given the same seed) you should use any of the 192 bits to form a 128 bit key - as long as you don't reuse any bits of course. If the 128 bits are not secure, then the 192 bits should also not be secure. AES keys consist of bits that are entirely random and thus unrelated, so generating a 192 bit ...


3

I'm not sure I understand your question entirely. If there is only one possible message, then the ciphertext can be trivially decrypted simply by choosing this message. I'll assume instead that the ciphertext contains the shuffled bit pattern of a name chosen from a set of more than one name. The problem with bit shuffling is that the number of set bits ...


7

Let's consider the notion of IO (indistinguishability obfuscation). Informally, the definition states that for every two circuits $C_1$ and $C_2$ such that $C_1(x)=C_2(x)$ for every $x$, it holds that $IO(C_1)$ is computationally indistinguishable from $IO(C_2)$. That is, a distinguisher knowing $C_1$ and $C_2$ and given an obfuscation of one of them cannot ...


3

Strictly speaking, we can't know for sure that the output of AES is indistinguishable from random noise. It's conjectured to be true but no "proof" of that fact exists. For most commonly-used ciphers, it is conjectured that their output is indistinguishable from random. Specifically, modern ciphers are conjectured to be "strong pseudorandom permutations", ...


4

The NIST source you link to is SP 800-90B. If you look at the other two publications in the series: 90A and 90C, you can find explanations of how you can use a TRNG to instantiate a DRBG or requirements on how to condition the entropy. Here is what section 7.1 of 90A says about entropy input to a DRBG: Ideally, the entropy input will have full entropy; ...



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