php - Should I encrypt email addresses?

Question

When users register, should I store their email in the db as is or hash it. I want to be able to decrypt it later, so should I use md5?

thank you!

Answer 1

No, md5() - is one-way hash function. You can't decrypt its value. Usually it used for passwords which don't need to be decrypted. Instead you compare hashes like:

$salt = "adding some secret to increasse security";
if (md5($user_password . $salt) == $user_password_hash_from_db) {
    ## password is ok
}

If you want to be able to decrypt your value, then use crypt php function instead. But it may require additional modules to be installed.

Any way I don't see any practical reason to crypt email.