Scrypt is key derivation function (KDF) developed by Colin Percival and published in 2012. A KDF is a computationally intensive algorithm that uses passwords to secure data, with the security mainly based around requiring large amounts of memory to complete operations. For a legitimate user, the operation is quick and completes in a little under a second. If a user is trying to attack using a brute-force method, the operation would have to be completed billions of times, which makes it nigh impossible to get through the security system in a reasonable amount of time.