Cryptocurrency and Blockchain Dictionary

51% Attack

A ‘51% attack’ refers to a possible attack on a blockchain by a group of ‘miners’, who hold more than 50% of the hashrate. In such a situation the ‘miners’ have the possibility to deliberately not confirm transactions or to issue transactions twice (double-spend).

Airdrop

An airdrop is a way to distribute coins. End users can generally get coins for free or in exchange for a small task, such as subscribing to a newsletter, sending a tweet or inviting other people via a personal affiliate link.  

2 Factor Authentication (2FA)

2 Factor Authentication is a double layer security measure. Most crypto exchanges use it. In order to log in, you not only need to enter a password, but also a code that you receive from the Google authenticator for example.

Block explorer

A block explorer is an online service to track blockchain transactions. It usually is a website where you can see all the new blocks that are being created. You can also search for transactions and wallet addresses. The best-known block explorers are blockchain.info for Bitcoin and etherscan.io for Ethereum.

Anti-Money Laundering

AML is the abbreviation for ‘anti-money laundering’. AML stands for policy and legislation on money laundering. This prevents illegally acquired funds from being converted into a legal variant. Within the crypto world, it is no longer unusual for AML techniques to be used by exchanges and wallets. This term is often used as AML/KYC, where KYC stands for ‘Know your customer’.

Block Reward

The block reward is the payment that is offered to the node that is securing the blockchain. In the case of Bitcoin, which is has a Proof-of-Work consensus algorithm, these would be the miners. The payment is in the form of the native cryptocurrency of that blockchain. The amount is a predetermined reward per block, but often that is supplemented with the fees that are paid for the transactions that block contains. For Bitcoin the current block rewards are cut in half every four years. This is called the ‘halvening’.