Secret Server's User passwords and DoubleLock passwords are hashed in the database using the SHA 512 hashing function. A hash function differs from an encryption method, such as AES, because a hash function when used correctly is computationally infeasible to reverse
Hashing algorithms are mathematical functions to convert inputted text values to a hash digest. Even the most minor change of the input text produces radically different hashed values. This guarantees that if two users use the same password, their hash value in the database will not be the same.
Hashing is an essential security requirement to ensure that authentication credentials are not exposed.
Secret Server also uses random salts and multiple hash iterations to prevent brute-forcing and the use of Rainbow tables.
More in depth information on SHA-512
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