User Privileges using dblink

Hello,

we want use dblink to connect several databases in a client/server environment. Connection from local users to the
remotedatabases should be possible only for privileged users. We tried a solution with dblink, embedding this command
ina view, like this: 

create view inst as select * from dblink('host=pollux port=5432 dbname=cob_int user=his_int password=#integration#',
.....

This solution is insecure, because login and password is readable for everyone.

We tried to call dblink without username and login, but it fails,i.e.

 create view inst as select * from dblink('host=pollux port=5432 dbname=cob_int', .....

What we are searching for, is a solution which uses the current login information (user and password).


The second problem with dblink is a security hole. If you have a table without any grants for the current user, this
usercan create a view to circumvent the table privileges, i.e.. 

Current user is svawork (not a superuser!). Current database is sva4_int1. Table inst has privileges only for a user
sva.If user svawork tried to read from inst it fails. This is ok.  
If svawork create a view like:

create view myinst as select * from dblink('dbname=sva4_int1','select .... from inst') as (.......);

The view connect not to a remote database. It uses the local database.
You can read the data from table inst without any restrictions! (Select * from myinst ...)
This problem could also be resolved, if dblink uses the current login information.

Any solutions welcome.

Karsten