Cryptographic Hash Function
Hash is an algorithm that always converts input data to other values of a certain length, independent of the original. Among them, cryptographic hash functions are those designed to prevent the recovery of converted strings to their original data.
If the password is stored as a hash, reading the database will not reveal the original password. However, when the user logs in, if the input string is converted to the same hash algorithm and compared with the stored value, it is possible to verify the password without knowing the original.
MD5, SHA-1, SHA-2, and SHA-3 algorithms are widely used for cryptographic hash functions. Among them, MD5 and SHA-1 are old algorithms, and many mathematical attack methods have been studied and are now known to be vulnerable. However, unsecure means that a group with sufficient funds can crack the password in a meaningful amount of time, not that an individual can easily crack the original string.SHA-1 Hash Wiki »