DDoS is a distributed attack in which many devices simultaneously flood a server with requests to overload it and make it unavailable to ordinary users. It is a frequent threat to crypto exchanges and pools.

Double spending is an attempt to spend the same coins twice. This is a key problem of digital money, which the blockchain solves using a distributed ledger and transaction confirmations.

A paper wallet is a way of storing cryptocurrency in which the public address and private key are printed out on paper. It is a form of cold storage that is kept offline, away from the internet.

Identity verification is the procedure of confirming a user's personal data on an exchange or service. It is needed for account security and access to withdrawing funds.

AML (Anti Money-Laundering) is a set of legal and technical measures designed to prevent the legalization of illegally obtained funds through cryptocurrency services and exchanges and to make the industry more transparent.