L9: Bitcoins and Cryptocurrency Flashcards
Cryptographic hash functions do not have a key
True
A major drawback of cryptographic hash functions is that it is easy to find two messages that have the same hash value.
False
Cryptographic hash functions are primarily used for message integrity.
True
The security of cryptocurrency ledgers depends on the honesty of its miners.
True
Most cryptocurrencies are designed to maintain production, to keep inflation in check
False
Since cryptocurrencies are pseudo-anonymous it is okay that they are more susceptible to law envorcement seizure.
False
Changing a block requires regenerating all successors and redoing the work they contain
True
In a _____ attack, the attacker creates a lot of fake identities and uses them to change voting outcomes or control a network.
Sybil attack
A sybil attack is designed to attack reputation systems in a peer-to-peer network
True
Sybil attacks can be stopped if users are willing to give up anonymity
True
In Bitcoin, attacks are infeasible if majority of miners weighted by hash power follow the protocol
True
In Bitcoin, an attacker who controls 51% of the computing power in the network can steal coins from existing addresses.
False
In Bitcoin, an attacker who controls 51% of the computing power in the network can suppress some transactions from the block chain.
True
In Bitcoin, an attacker who controls 51% of the computing power in the network can change the block reward.
True
Hot storage wallets are _______.
Online
