Attacking proof of work

Security Assumptions

• The hash function used in the algorithm should be secure, meaning it is a one-way function and has collision resistance.

• The difficulty level should be set appropriately to ensure that the difficulty of finding a valid block header is proportional to the hash rate of the network.

• The majority of miners in the network are assumed to be honest.

Violation of Security Assumptions

• If the hash function is not secure, a miner who discovers this fact can gain an unfair advantage.

• If the difficulty level is set too high, it could lead to a denial of service attack where blocks are not being created.

• If the difficulty level is set too low, an attacker could create a malicious version of the blockchain that becomes longer than the legitimate one.

• If the majority of miners are dishonest, the proof of work algorithm fails.

Vulnerabilities

• 51% Attack: If an attacker controls more than 50% of the network's hash power, they can potentially manipulate the blockchain by creating a longer chain of blocks.

• Denial of Service Attacks: If the difficulty level is set too high, it can prevent the creation of new blocks, causing a denial of service.