Cisco 6921 Administration Manual page 30

Understanding Security Features for Cisco Unified IP Phones
Table 1-6 Overview of Security Features
Feature
Image authentication
Customer-site certificate installation
Device authentication
File authentication
Signaling Authentication
Manufacturing installed certificate
Secure SRST reference
Media encryption
Signaling encryption
CAPF (Certificate Authority Proxy
Function)
Security profiles
Encrypted configuration files
Cisco Unified IP Phone 6921, 6941, and 6961 Administration Guide for Cisco Unified Communications Manager 8.0 (SCCP)
1-16
Description
Signed binary files (with the extension .sgn) prevent tampering with the
firmware image before it is loaded on a phone. Tampering with the image causes
a phone to fail the authentication process and reject the new image.
Each Cisco Unified IP Phone requires a unique certificate for device
authentication. Phones include a manufacturing installed certificate (MIC), but
for additional security, you can specify in Cisco Unified CM Administration that
a certificate be installed by using the Certificate Authority Proxy Function
(CAPF). Alternatively, you can install a Locally Significant Certificate (LSC)
from the Security Configuration menu on the phone. See the
Security on the Cisco Unified IP Phone" section on page 3-13
information.
Occurs between the Cisco Unified CM server and the phone when each entity
accepts the certificate of the other entity. Determines whether a secure
connection between the phone and a Cisco Unified CM should occur; and, if
necessary, creates a secure signaling path between the entities by using TLS
protocol. Cisco Unified CM will not register phones unless they can be
authenticated by the Cisco Unified CM.
Validates digitally signed files that the phone downloads. The phone validates
the signature to make sure that file tampering did not occur after the file creation.
Files that fail authentication are not written to Flash memory on the phone. The
phone rejects such files without further processing.
Uses the TLS protocol to validate that no tampering has occurred to signaling
packets during transmission.
Each Cisco Unified IP Phone contains a unique manufacturing installed
certificate (MIC), which is used for device authentication. The MIC is a
permanent unique proof of identity for the phone, and allows Cisco Unified CM
to authenticate the phone.
After you configure a SRST reference for security and then reset the dependent
devices in Cisco Unified CM Administration, the TFTP server adds the SRST
certificate to the phone cnf.xml file and sends the file to the phone. A secure
phone then uses a TLS connection to interact with the SRST-enabled router.
Uses SRTP to ensure that the media streams between supported devices proves
secure and that only the intended device receives and reads the data. Includes
creating a media master key pair for the devices, delivering the keys to the
devices, and securing the delivery of the keys while the keys are in transport.
Ensures that all SCCP signaling messages that are sent between the device and
the Cisco Unified CM server are encrypted.
Implements parts of the certificate generation procedure that are too
processing-intensive for the phone, and interacts with the phone for key
generation and certificate installation. The CAPF can be configured to request
certificates from customer-specified certificate authorities on behalf of the
phone, or it can be configured to generate certificates locally.
Defines whether the phone is nonsecure or encrypted. See the
Security Profiles" section on page 1-17
Lets you ensure the privacy of phone configuration files.
Chapter 1 An Overview of the Cisco Unified IP Phone
"Configuring
for more information.
for more
"Understanding
OL-20851-01