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Xoops is the main site, the page you go to first, so I would use Xoops authentication. they both require the same info.
looking at the xopos "users" table, only the password is encrypted
looking at the other "users" table, again the password is encrypted, but there is also a lot more info required. Address, city, country, postal code, phone, birthdate
but i believe i can "activate" those fields in the xoops registration also