There are four settings that need to be correct in order for SecurityExpressions to use an Oracle Database.  First the file TNSNAMES.ORA must have the correct information.  Below is an example simple TNSNAMES.ORA

# TNSNAMES.ORA Network Configuration File: E:\oracle\ora92\network\admin\tnsnames.ora
# Generated by Oracle configuration tools.

PMP.CSTEST.COM =
  (DESCRIPTION =
    (ADDRESS_LIST =
      (ADDRESS = (PROTOCOL = TCP)(HOST = pmultiprocessor.pedestal.com)(PORT = 1521))
    )
    (CONNECT_DATA =
      (SERVICE_NAME = pmp.pedestal)
    )
  )

The second file is SQLNET.ORA.  Below is an example simple SQLNET.ORA:

# SQLNET.ORA Network Configuration File: E:\oracle\ora92\network\admin\sqlnet.ora
# Generated by Oracle configuration tools.

NAMES.DEFAULT_DOMAIN = cstest.com

SQLNET.AUTHENTICATION_SERVICES= (None)

NAMES.DIRECTORY_PATH= (TNSNAMES, ONAMES, HOSTNAME)

The third setting is the Server name.   The Server name in the Microsoft ODBC for Oracle setup screen must be the same as in TNSNAMES.ORA, in this example PMP.CSTEST.COM.

The fourth setting is the SQLNET.AUTHENTICATION_SERVICES, it must be (None).