I can place SSL without buying the digital, necessary certificate of one https more only for transferencia security the login members

you can self-sign the certificate, but the users will get a warning in their browser to that effect.

before you enable mod_ssl in apache, make sure you have upgraded apache and openssl to the latest versions, otherwise you will have a remote root hole on your box - infinitely worse than the minute risk of a man in the middle attack on your visitors' traffic.

paul