CERTICOM APPLICATION NOTES

Certicom Security for Sensor Networks
Ensuring security
Security inin wirelessWireless sensor
Sensor networks
Networksensuring

THE CHALLENGE
The list of applications for wireless sensor networks is constantly growing. Companies and government organizations
are recognizing the potential of these networks to enable everything from asset tracking in warehouses to temperature
control in office buildings. Their advantages are many: they deploy rapidly and re-deploy with great flexibility due to theirwireless nature. They’re cost-effective to maintain and to operate, and they scale easily.
Most sensors in such networks are conveniently compact: often single-purposed battery-powered units and are usually
fairly simple.
Yet that compactness and simplicity can be problematic where security is concerned. It is difficult to preserve economy
and efficiency and at the same time give sensor nodes enough intelligence to support some of the more sophisticatedfunctions required to ensure the security of the network and the information it transmits.

Why Security Is Essential
The entire value proposition for sensor networks hinges on the expectation that they will function as designed. Failures—
whether produced by error or attack—can have exactly the opposite effect of what was intended, creating downtime,interfering with efficiencies and increasing costs.
The prospect of such failures is unpleasant both for network vendors and for their customers. Vendors, particularly, standto lose reputation and business if their networks can’t hold up their end of the bargain.
To prevent calamities, the sensor network must be secured against unauthorized use—again, whether accidental ormalicious. This requires authentication and access control.
Most often today, these are established through centrally managed key exchanges: a central controller verifies nodeidentities and distributes the keys for nodes to establish secure connections. This works for small and self-contained
networks, but does not permit easy growth. An apt analogy for the central controller is the traffic cop: he or she may beable to manage a busy intersection, but any increase in lanes, streets or traffic could quickly get out of hand.
There are several practical challenges associated with this model:•establishing connections between networks—because nodes don’t have the intelligence to know which controller
to take direction from;•requiring nodes to request direction from a controller can introduce delays and increase network complexity;and•centralized control creates a central point of failure for a secured network.

CERTICOM SECURITY FOR SENSOR NETWORKS

So what’s the alternative?
Flexible, decentralized mesh architectures allow sensor networks to grow and interoperate easily. Within such an architecture,public-key-based authentication and security allows nodes to operate independently and collaboratively. Each device isissued its own keys and security policy. Identities and policies can be created centrally, then distributed to nodes to enablenetwork operation.

Network #1
Network #2

provides security
policyPolicy Infrastructure
FIGURE 1: With public-key nodes operate independently and create secureconnections by authenticating other nodes.

REQUIREMENTS SCENARIOS
To appreciate how security is required—and must be enabled—in wireless sensor networks, consider the following real-world
examples.

Keeping It Under Control
Increasingly, wireless sensor networks are being deployed to assist with commercial building controls such as those for lighting
and energy-management systems. In such cases, network operators promise their clients that the systems will help reduce
lighting, heating and other costs through superior control of building conditions. With lighting costs alone making up 20 to 30
percent of operating expenses, this is an enormously appealing proposition.
To deliver the full benefits, operators must be sure their networks are protected against rogue nodes, active attacks and evenuser error—by securing every sensor node individually and by ensuring that access to the system is restricted to authorized
nodes only. It’s a business imperative, because the operator’s reputation depends on the performance of the network.

2

CERTICOM SECURITY FOR SENSOR NETWORKS

Safety-first Systems
Perhaps even more business-critical are alarm-monitoring networks involving motion sensors or smoke and fire detectors. In
these cases, the monitoring is provided as a commercial service—and failure to perform could result in the loss of or damage toproperty and information. People’s safety may even be at risk.
In both this and the previous example, some measure of flexibility is also required. Client organizations must be able to grow orreconfigure their physical space and have their sensor networks keep up with the changes as effortlessly as possible.

The Public-key Advantage
Public key-based networking enables nodes to operate independently and collaboratively. Each device is issued its own keys
and security policy. Identities and policies can be created centrally, then distributed to nodes to enable network operation.
For building systems control and alarm monitoring applications, this kind of public-key infrastructure allows each node
to operate with some autonomy, protecting the network in an unencumbered and easily reconfigurable way. It enables
validation of all monitoring equipment. And the secure key exchange between a variety of nodes protects the data being
monitored and shared.
The public-key model also addresses the complexities that arise from the interactions of proprietary, open-source andconsortium-driven sensor networking technologies. A provable identity based on public-key can be used by the same back-end
systems, independent of the type of network that is in use. In other words, public-key identification is technologically ‘portable’.

THE SOLUTION
Certicom Security for Sensor Networks allows developers of low-power sensor devices to build secure, reliable operation
into networks from the very beginning of the process, rather than having to add it on later. Its public-key-based operation
eliminates the need for centralized control of node identities. Instead, Certicom distributes security functions throughout thenetwork to each of the individual sensor nodes. This supports the establishment and maintenance of sensor networks that arescalable, fluid and easily reconfigurable—providing capabilities for an array of new and innovative applications.

The Components
Security Builder MCE (Microcontroller Edition)
Cryptographic Software Module for Low-power Devices
Security Builder MCE provides the cryptographic primitives required to create a trusted platform for low-power devices.
In addition to symmetric encryption, it allows you to integrate key exchange and digital signatures based on elliptic curve
cryptography (ECC): the only public-key scheme capable of meeting the footprint and power limitations of these constrainedenvironments. Security Builder MCE provides an API to the device networking stack, and can deliver even stronger performance
when combined with the Certicom f(2m) IP Core.
Certicom IP Core
Hardware IP Core for the Acceleration of ECC on Low-power Devices
The Certicom f(2m) IP Core accelerates processor-intensive finite-field ECC operations, which are otherwise prohibitively slow formany embedded applications, enabling low-power devices to benefit from the improved security of public-key cryptography.
The f(2m) hardware core accelerates public-key operations over elliptic curves of characteristic 2. It operates in concert withSecurity Builder MCE to interface with the device networking stack.

3

CERTICOM SECURITY FOR SENSOR NETWORKSOUTCOMES
Certicom Security for Sensor Networks provides the missing link that allows sensor networks to fulfill their true potential—
flexibly and securely.
Specifically, it gives the network a decentralized way to validate the identity of participating nodes; to establish communication
between nodes; to encrypt data for information security; and to enable integrity checking that ensures messages have notbeen altered or corrupted.
Using public-key technology spreads operational capability and intelligence among the network nodes—while still allowing forcentralized administration of the network’s security policies. It is simply that each of the nodes has the ability to enforce thosepolicies independently.
Certainly, permitting device mobility and ensuring standards-level security is not required for every sensor network. In homecontrols, for example, the requirements for authentication and protection are minimal, and symmetric-key security is likely tobe acceptable. For higher-value systems, however, public-key security enabled by the Certicom solution provides a better way tomanage device identities and deliver strong security.
Certicom works with application vendors to ensure that the capabilities offered through public-key operations are extended
from the device up to sensor network applications.

About Certicom

Certicom, a wholly owned subsidiary of Research In Motion Limited (RIM) (Nasdaq: RIMM; TSX: RIM), manages and protects the value of content, applications and devices withgovernment-approved security. Adopted by the National Security Agency (NSA) for government communications, Elliptic Curve Cryptography (ECC) provides the most security per
bit of any known public-key scheme. As the global leader in ECC, Certicom’s security offerings are currently licensed to hundreds of multinational technology companies, including
IBM, General Dynamics, Motorola and Oracle. Founded in 1985, Certicom’s corporate office is located in Mississauga, Ontario, Canada with worldwide sales offices in USA and Asia.
Visit www.certicom.com.
USA3600 Glen Canyon Rd., Suite 1
Scotts Valley, CA 95066
USA
Tel: 1.831.438.4100
Fax: 1.831.438.4111
Sales: 1.800.561.6100
Corporate Headquarters
sales@certicom.com

Tel: +1.905.507.4220
Toll Free: 1.800.561.6100 (NA only)

Corporate Headquarters
5520 Explorer Drive, 4th Floor
Mississauga, ON L4W 5L1Canada
Tel:1.905.507.4220

Toll Free: 1.800.561.6100(NA only)Japan
Research In Motion Japan Ltd.
Nippon Brunswick, Building 7F
5-27-7 Sendagaya,Shibuya-ku,
Tokyo 151-0051, Japan
Tel: 03 6367 3567
sales@certicom.com

United Kingdom
Japan
info@certicom.com
Tel: +44 1344 624970
Research In Motion Japan Ltd.
Tel: 03 6367 3567

© 2010 Certicom Corp. Certicom, Certicom AMS, ACC, Asset Control Core, Certicom Bar Code Authentication Agent, Certicom ECC Core, Certicom Security Architecture, Certicom Trusted Infrastructure, Certicom CodeSign,Certicom KeyInject, ChipActivate, DieMax, Security Builder, Security Builder API, Security Builder API for .NET, Security Builder BSP, Security Builder Crypto, Security Builder ETS, Security Builder GSE, Security Builder IPSec,Security Builder MCE, Security Builder NSE, Security Builder PKI, Security Builder SSL and SysActivate are trademarks or registered trademarks of Certicom Corp. BlackBerry®, RIM®, Research In Motion® and relatedtrademarks are owned by Research In Motion Limited. Used under license.

SwedenTel: +46 8 747 17 41