 Darknet markets, also known as crypto markets, allow buyers and sellers to interact without revealing their true identities, providing a largely anonymous platform for trading in a range of illicit goods and services, including drugs. To achieve anonymity during a transaction, the payment must also be carried out anonymously. This is achieved by using cryptocurrencies such as Bitcoin. To obtain Bitcoins, the user has to establish a digital wallet. Users then buy Bitcoins on exchange websites or using mobile applications. These Bitcoins are stored in the wallet and are available for purchases. When a user initiates a payment, the transaction is pending. Once it is verified and approved, the Bitcoins are transferred to the seller's digital wallet and the transaction is recorded in the blockchain, a public unencrypted ledger stored on a decentralized network. The records contained in the blockchain allow the transaction to be traced back to the point where the Bitcoins were purchased. To avoid this, obfuscation systems may be used, presenting an additional challenge to law enforcement investigations.