Quote from: Jason Brendon on Today at 07:19:22 AM

with such powerful hash rate, will it be used to brute force against our private keys? I guess the answer is no. but since the power of hashrate increases, all private keys will be brute forced. I certainly don't mean now or anything close.

There are two reasons why not:

The astronomically huge amount of computation required to break a private key is still many orders of magnitude above the amount of computation that the Bitcoin network can perform. (See below for a brief description of how much computation would actually be required in various scenarios.)
“ASIC” stands for ‘Application-Specific Integrated Circuit’. “Application-Specific” means just that: The ASICs used for Bitcoin mining have the mining algorithm baked into the hardware. They cannot be repurposed for anything else.

Quote from: hosseinimr93 on Today at 07:26:10 AM

Quote from: Jason Brendon on Today at 07:19:22 AM

with such powerful hash rate, will it be used to brute force against our private keys? I guess the answer is no.

That's not possible.
Each private key provides 128 bits of entropy.

That is flatly incorrect. A secp256k1 private key has slightly less than 256 bits of entropy. But that is irrelevant:

Most public keys needed to spend funds are not publicly revealed. For P2PKH and P2WPKH addresses that have not been reused, all that is publicly known is a 160-bit hash of the public key—not the public key itself. Thus, for those, the search space for bruteforce is 2¹⁶⁰.
When a public key is known, an attacker would use an ECDLP solver, not bruteforce. Bitcoin’s public-key security level is 128 bits, even though the private keys themselves are 256-bit numbers (slightly restricted within that range). No attacker would use brute force.

Asking questions is good; giving bad answers is bad. People need to stop tossing out nonsense that is like the blind leading the blind.

Quote from: Jason Brendon on Today at 07:19:22 AM

But one day.. with quantum computer..

Quote from: un_rank on Today at 07:34:16 AM

If quantum computers can break that encryption, then bitcoin would be one of many systems affected, since it is currently more secure than others.
Maybe there would be a security update when that situation is at hand.

A quantum computer could solve the ECDLP using Shor’s Algorithm.

Bitcoin’s public keys are used for digital signatures, not encryption.

Quote from: Charles-Tim on Today at 09:12:30 AM

That is why mining difficulty is adjusted every 2016 blocks. It is like that because if more miners join the network, the mining hashrate increases, and this will lead to transactions getting confirmed more below 10 minutes. But if miners stop their miners from working and are not mining, the hashrate will reduce and transactions will be getting confirmed more above 10 minutes.

Hashrate variance usually has much less effect on what users observe than the variance that is statistically expected on the exponential distribution.

I suggest that you reread my post immediately prior to yours, and stop fixating on the 10-minute number. The 10-minute number is relevant to difficulty retargeting, over an average of 2016 blocks. It is not a useful predictor of what users actually want to know: “When will my transaction confirm?”