Cassandra - Datacenter data segregation - database

Question

I am setting up an Apache Cassandra cluster and I want to segregate certain data to only certain datacenters. I know I can limit where the data is stored via replication factor, but that is not enough.
I have the keyspaces DC1DATA, DC2DATA, ALL, and I want my DC1 data to be
A) stored in DC1 - solved via replication factor
B) inaccessible from DC2 (like you cannot run a select statement even as admin user)
And I want both datacenter having access to the "ALL" keyspace.
Can I do that somehow?
This is what I am doing for setting up the keyspaces (example had 1 node x datacenter, total 2 nodes):
CREATE KEYSPACE dc1data
WITH REPLICATION = {
'class' : 'NetworkTopologyStrategy',
'dc1' : 1
} ;
CREATE KEYSPACE dc2data
WITH REPLICATION = {
'class' : 'NetworkTopologyStrategy',
'dc2' : 1
} ;
CREATE KEYSPACE all
WITH REPLICATION = {
'class' : 'NetworkTopologyStrategy',
'dc1' : 1,
'dc2' : 1
} ;
but I can still connect to any node in DC1 and do
cqlsh> use dc2data;
cqlsh:dc2data> create table if not exists test (
name text,
lastname text,
primary key ((lastname),name)
);
cqlsh:dc2data> insert into test (name, lastname) values ('Homer','Simpson');
cqlsh:dc2data> select * from test;
lastname | name
----------+----------
Simpson | Homer
That is what I want to avoid: seeing the dc2data keyspace from dc1, at all. Is that possible? Even to admin users?