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It is also important that you append a salt to the password you are hashing. A salt is a randomly generated piece of data that is stored along with the hash value. The use of a salt helps prevents dictionary attacks against the hash value, provided the salt is long enough what is long enough . Each password should have its own salt associated with it. If a single salt were used for more than one passwordspassword, two users would be able to see if their passwords are the same.
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