most secure password scheme

[Aki Tuomi]

I would go with SHA512-CRYPT, since it is compatible with lots of other things. The field length is static and it contains ascii characters, and it appears to be 118 characters long, but it might be a good idea to use varchar(255) nevertheless, in case you decide to use something else someday.

With mysql, you can do

mysql> SELECT ENCRYPT('hello','$6$rounds=4000$s9Zc4OA11IuLt/iV');

i would advice using rounds for extra security, but this is of course up to you. The rounds parameter will make the algorithm to do 4000 rounds of SHA512 to make it less feasible to do brute force attacks.

Aki

> On April 30, 2017 at 4:59 AM David Mehler <dave.mehler at gmail.com> wrote:
> 
> 
> Hello,
> 
> Thanks for the explanation. So should I go with SSHA512 or
> SHA512-CRYPT? From your explanation i'm interpreting to mean that
> SHA512-CRYPT also salts. This is for storing in a mysql database.
> Also, what should the password field length and type be set for?
> Currently it's varchar(128)
> 
> Thanks.
> Dave.
> 
> 
> On 4/29/17, Aki Tuomi <aki.tuomi at dovecot.fi> wrote:
> >
> >> On April 29, 2017 at 4:22 AM David Mehler <dave.mehler at gmail.com> wrote:
> >>
> >>
> >> Hello,
> >>
> >> I have a few questions on password schemes. Is SHA512 the most secure?
> >> Is there a difference between SHA512 and SHA512-CRYPT? What about
> >> SSHA512 and SSH512-CRYPT?
> >>
> >> Is there a problem with this sql statement:
> >>
> >> UPDATE virtual_users SET password=CONCAT(‘{SHA256-CRYPT}’, ENCRYPT
> >> (‘Password Goes Here’, CONCAT(‘$5$’, SUBSTRING(SHA(RAND()), -16))))
> >> WHERE user=’user at example.com’;
> >>
> >> I'm getting an error 1064 at the ending email address.
> >>
> >> Thanks.
> >> Dave.
> >
> > SSHA512 is salted SHA512, SHA512-CRYPT is crypt(3) compatible salted hash.
> > PCKS5 or SHA512-CRYPT with over 1000 rounds is probably very secure, but
> > SHA512-CRYPT is also good. Using SHA512 is not recommended, as it's unsalted
> > hash.
> >
> > If ENCRYPT is same as crypt(3) then you can try put rounds into salt, like
> > "$6$rounds=4000$s9Zc4OA11IuLt/iV$".
> >
> > Aki
> >