6 ms·

There is no safe way to wind down mining. As mining becomes unprofitable, mining equipment will be shut down. But it will still exist, and it will be in the han

There is no safe way to wind down mining. As mining becomes unprofitable, mining equipment will be shut down. But it will still exist, and it will be in the hands of people desperate for cash. This means that the price of 51% attack will drop massively, and that completely undermines the safety that PoW provides. A large drop in price followed by a large drop in mining completely destroys the security of bitcoin.

tromp 5y ago
The price of a 51% relative to the total marketcap won't change drastically (only moderately due to wider availability of hardware), and that's what security is based on, not the absolute cost of a 51% attack.
- lottin 5y ago
  No... security depends on the cost mounting an attack, and that's the absolute cost.
  - tromp 5y ago
    No... a chain that costs $1M to attack with a mktcap of $100K is more secure than a chain that costs $10M to attack with a mktcap of $100B, as the latter has huge financial incentives for doublespending (after depositing say $100M at an exchange), while the former has none. It's like how much you spend on a bike lock. A $100 lock on a $20 bike is probably quote secure, while a $200 lock on a $5000 bike is probably quite insecure.
    - lottin 5y ago
      No... an attacker that is able to successfully execute a 51% attack can crash the token price and make enormous profits in the derivatives market, so the market cap is irrelevant. Moreover, and attacker may have motivations other than financial gains, which again makes market cap irrelevant. If your security model only protects against financially motivated attackers it means it's basically rubbish.
- user-the-name 5y ago
  The "total market cap" is a completely fictional number that represents nothing real whatsoever. It makes no sense to compare anything to this number.

6 ms·

There is no safe way to wind down mining. As mining becomes unprofitable, mining equipment will be shut down. But it will still exist, and it will be in the han

by user-the-name 5y ago

tromp 5y ago
The price of a 51% relative to the total marketcap won't change drastically (only moderately due to wider availability of hardware), and that's what security is based on, not the absolute cost of a 51% attack.
- lottin 5y ago
  No... security depends on the cost mounting an attack, and that's the absolute cost.
  - tromp 5y ago
    No... a chain that costs $1M to attack with a mktcap of $100K is more secure than a chain that costs $10M to attack with a mktcap of $100B, as the latter has huge financial incentives for doublespending (after depositing say $100M at an exchange), while the former has none. It's like how much you spend on a bike lock. A $100 lock on a $20 bike is probably quote secure, while a $200 lock on a $5000 bike is probably quite insecure.
    - lottin 5y ago
      No... an attacker that is able to successfully execute a 51% attack can crash the token price and make enormous profits in the derivatives market, so the market cap is irrelevant. Moreover, and attacker may have motivations other than financial gains, which again makes market cap irrelevant. If your security model only protects against financially motivated attackers it means it's basically rubbish.
- user-the-name 5y ago
  The "total market cap" is a completely fictional number that represents nothing real whatsoever. It makes no sense to compare anything to this number.