Quote from: NinjaBitcoiner on November 16, 2022, 04:44:29 PM

So a bitcoin private key is actually a random integer between 1 and 2^256 right and bitcoin wallet generate it randomly by using PRNG.

A little lower than 2^256, and yes.

Quote from: NinjaBitcoiner on November 16, 2022, 04:44:29 PM

Ok so what's stopping PRNG from choosing say a random integer between 1 and 100000? Won't that make your private key insecure?

Cryptographically secure pseudo-random number generators aren't really random, and that's why they will never return you number 1000000 (e.g.) in such a large given range. The numbers they return look random.

Quote from: NinjaBitcoiner on November 16, 2022, 04:44:29 PM

How to make sure the private key generated by bitcoin wallet is high quality?

You can put some trust in the experts around cryptography, using clean OS and vulnerability-free hardware, and make usage of the system's internal CSPRNG. Otherwise, you can roll a fair dice, and generate the entropy yourself, provably randomly.