Securing the Smart Grid with SafeNet S afeNet HSMs WHITEPAPER W WH HITEPAPER
Overview The smart grid is the first major effort to modernize an energy infrastructure that has remained largely unchanged over the past several decades. The smart grid creates a network of links between customers and utility companies that provides increased insight into and management of energy consumption, cost, and workload across the entire energy grid. At a time when energy utilities play an increasingly important part of our everyday lives, smart grid technologies introduce new security challenges that must be addressed. Implementing a smart grid without proper security could result in grid instability, loss of private information, utility fraud, and unauthorized access to energy consumption data. Building a trusted smart grid will require robust security solutions, and interoperability from multiple vendors, that can be easily deployed at the communication and application layers of the smart grid infrastructure. In the first phase of smart grid deployments, traditional meters will be replaced with meters that can be read remotely, called smart meters. The Advance Metering Infrastructure (AMI) is the second phase of the smart grid and uses smart meters to enable a two-way channel of communication between meters and the utility company. Securing this two-way line of communication is imperative, and will require a solution for Head End Trusted Identity authentication and Smart Meter device attestation to ensure the integrity of the grid. Leveraging this integrity will allow utilities to both; issue trusted firmware upgrades on deployed smart meters, and verify data from smart meters coming back to the deployed Head End Systems. This system integrity will maintain security, and minimize cost footprint of upgrades to the deployed smart meters. A critical component of smart grid security is cryptography and key management, which will ensure confidentiality, authenticity, and integrity of devices and communications within the grid. Every cryptographic system needs strong protections for the top-level cryptographic material used to provide the systems trust anchor. Typically, compromise of these top-level keys results in complete or at least very broad system-wide compromise. This is where hardware security modules offer significant trust value.
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HSMs Role in the Smart Grid Smart grid security solutions must be able to deploy on a large scale, with minimal effect on applications. Securing the smart grid at the communication layer will require a system to identify connected meters, to verify that these meters are configured correctly, and to validate these meters for network access. The recommended solution for this authentication process is an identity based model, often a Public Key Infrastructure (PKI). PKIs are ideal for large-scale security deployments that require a high level of security with minimal impact on performance. In a PKI environment, it is essential that private keys and certificates are guarded with a reliable key management solution that protects against ever-evolving data threats, such as hardware security modules (HSMs). HSMs require secure interoperability with deployed Smart Grid infrastructures. For years, various industries have relied on HSMs for securing the most sensitive PKI environments. In fact, SFNT HSMs have a long standing history with large scale deployments in the financial industry, working to define and implement industry standard based deployments, and deployed to protect more financial transactions than any other HSM (more than a trillion Dollars day) applications. SafeNet HSMs offer a cost-effective PKI solution for easy deployment in smart grid infrastructures. With the SafeNet PKI Bundle, product and maintenance costs are dramatically reduced by combining HSM functionality that usually requires two or more HSMs into a single HSM “bundle” of modular functions. For CAs with certificates and root keys, for example, rather than requiring separate HSMs for key generation and key export for offline and online root CAs, the requirements can be fulfilled by one SafeNet HSM that stores keys in hardware to achieve FIPS 140-2 L3 security. In addition, with highperformance RSA, ECC, and AES cryptographic services, SafeNet HSMs are the only HSM in the industry that can keep up with the performance requirements of even the most complex advanced smart grid deployments. Generation
High Value Endpoints
Suppliers DR PKI
Device ID PKI
Provisioning PKI
Utility Engineering
Development Code Signing
Head-End Messaging
Production Code Signing
HAN
Utility Operations
PEV
End to End Security
HSMs Uses Related to Smart Grid Functions Device Identities. A SafeNet HSM performs many vital security functions during the manufacturing of smart grid devices. While issuing device identity certificates at the factory, the SafeNet HSM can protect both a sub-ordinate CA and registration authority (RA) key pairs, and secure signing key for any firmware or code loaded at manufacturing time. Hosting a sub-ordinate CA at the each manufacturing site isolates the site both operationally and cryptographically. HSM-supported RA functionality at the manufacturing site is important as the HSM provides high entropy RNG seed material and FIPS 140-2 Level 3-certified key generation for each device. The resource-constrained nature of smart grid devices makes Securing the Smart Grid with SafeNet HSMs Whitepaper
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it critical to ensure devices are provisioned with FIPS Validated high entropy seed material. Therefore, it is important to offer support for both CA and RA capabilities in the same HSM Bundle—SafeNet HSMs support this through the PKI Bundle feature without compromising security. Once manufactured with a trusted identity, a deployed device is expected to remain in the field for a long period, during that period the HSM is used to securely sign all firmware or Device ID updates in the field
Vendor
Root CA
Contract Manufacturers
DR CA Site
……
Utilities
Equipment vendors certifying device IDs at manufacturing
Device Provisioning. The same SafeNet HSM features and capabilities that support device issuance, as described above, can also be used by utility companies to provision devices within their infrastructures. In this case, deploying subordinate CAs at distribution centers, where meters and other devices are accepted into the utility’s control. Of course, this may be at a central office when provisioning is done during final installation at the site. Here, the utility either re-certifies the key pair created by the device manufacturer or generates their own completely new key pair and certificate. Device identities (certificates) are one part of the provisioning, HSMs are also leveraged for firmware updates and code signing -an equally important part of a secure end-to-end system. At this staging point, it is also critical to import into each device a trust root database, informing the devices which head-end systems to trust. Such device provisioning is required to maintain security, and minimize operational costs, in the long life expectancy of smart meters once deployed.
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Key Manager
Head End
Utility
PKI
HSMs in High Availability
Device Vendor
HSMs in High Availability
Device Manifests
Device S/N Customer ID ~Issue Device ID ~Seed Device
Pre - provisioned
Create/Certify ID Issue Utility keys
End Point Installer
From factory to deployment
Device Re-Certification. It would certainly be tempting to issue device certificates with very long lifecycles to avoid re-certification challenges altogether. However, this is not practical given the realities of the infrastructure. Devices fail and are replaced, devices require upgraded certificates, and the device firmware could get compromised—all leading to potential point of weakness. Because of this, device certificates and firmware need to have reasonable lifecycles and, therefore, utilities need the ability to re-certify the devices. The same set of SafeNet HSMs used for device provisioning can support re-certification. Of course, this is standard CA functionality but highlights another reason why utilities need their own PKI. Secure Message Processing. In smart grid infrastructures, the confidentiality, integrity, and authenticity of messages are critical. Meters need to accept commands only from authentic head-end systems, and the integrity and confidentiality of meter data must be assured. HSMs are critical in protecting the high assurance trusted head-end system Identities. Endpoint devices can use their certificates to sign and encrypt messages destined for the headend system. At the head-end messaging side, keys used to sign commands and messages directed to the endpoint are obviously high-value keys. A compromise of these keys could also compromise a substantial portion of the infrastructure. SafeNet HSM’s provide the security, performance, and reliability, and cross vendor interoperability required to support this function. SafeNet HSMs provide 5 9’s availability and high-performance RSA, ECC, and AES cryptographic services capable of supporting a wide range of secure messaging architectures. SafeNet HSMs are also capable of protecting very large quantities of keys, so it’s easy to ensure keys are used for only one purpose and to devise schemes that cryptographically segment a network into a large number of keys to provide further isolation within the infrastructure.
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Distribution Automation
Meter Data Mgmt System
Head End
HSMs in High Availability
Meter Reading Residential Generation
Meter Management Demand Management Pluggable Electric Vehicle
Digital envelope messaging
Device Authentication. Given the massive scale associated with many smart grid deployments, utilities need to carefully manage their certificate policies. Without proper segmentation and lifetimes, revocation schemes will quickly become overwhelmed. Segmenting a utility’s equipment cryptographically as discussed above is one component of the strategy. Another strategy is the use of On-Line Certificate Status responders. Traditionally, a head-end system would check an OCSP responder directly while validating a device’s certificate. However, a recommended approach has the end devices periodically collecting their own certificate status. The devices cache the responses, and then supply it to the head end with each message. This approach has the advantage of making the grid more robust to equipment failures, but has the disadvantage of broadening the attack footprint. A compromise of the OCSP responder key pair could then be used to supply fraudulent certificate status. SafeNet HSMs provide the performance and FIPS 140-2 Level 3 protectionsprotection of the OCSP responder private keys, offsetting the risk associated with caching certificate statuses. The HSM partitioning capability means the utility does not need a dedicated HSM to support the OCSP responder.
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DR PKI
Device Vendor Utility
Utility Root Federated Neighbors
…… Device ID
HSMs in High Availability
Regional Sub Roots
West
Central
East
Securing utilities segmented by domain
Infrastructure Trust Anchors. As utilities and smart grid vendors deploy PKIs within their solutions, they often choose to set up their own private PKI, as opposed to basing it on a public CA, however both are viable options. SafeNet HSMs are the market leader in both Enterprise PKI, and hosted PKI Services options. An Enterprise PKI provides the policy controls and assurance necessary that are not always available in a public CA. When deploying root CAs, it is common to keep the root offline and use it under very strict controls on a rare basis. The SafeNet HSM family includes small form factor, high security HSMs ideal for a root CA. These devices are small enough to be stored in a safe, provide all the security demanded by root key protection and, of course, interoperate with the rest of SafeNet’s HSM family.
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Smart Grid Distributed Generation and Storage
Utility
Infrastructure
Consumer
Encrypted Information
PKI and Key Management
HSMs for Root of Trust
HSMs are the secure root of trust for protecting the smart grid
Secure Management of Meters. Securely update the metering settings, configuration, security credentials, and firmware of all devices in the smart grid system. Signing and encryption of messages was discussed previously under the Secure Message Processing use case. In addition, SafeNet HSMs can be used to protect code signing keys. These high-value keys are used to sign firmware update images destined for endpoint devices. Compromise of these keys can lead to fraudulent software loads on devices, so an HSM is a natural place to host these keys.
Utility Engineering
Utility Operations
Secure over the air firmware update
Development Code Signing Production Code Signing HSMs in High Availability
HAN HSMs in High Availability
Suppliers Initial Production Firmware
Provisioning Installer
Secure firmware management
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HSMs Features Supporting Smart Grid Uses Compliance and Certifications: SafeNet HSMs have been validated to FIPS 140-2 Level 3 and Common Criteria EAL4+. They also facilitate compliance with PII, NIST, and NERC audits. HSM Partitioning. A key challenge in a smart grid is the overall scale of the deployments. It is not uncommon for a utility to have millions of endpoints. This leads to all sorts of challenges in the cryptographic management system, including the impact of a key compromise and management of the CRLs. One recommended strategy to address these issues is to cryptographically segment the utility into regions or groups. Establishing subordinate certificate authorities for each region or group limits the impact of any compromise. This segmenting scheme also helps manage the size of CRLs since they will be issued on a persegment basis. SafeNet HSMs support this approach through a secure flexible partitioning capability. A single physical HSM can be segmented into up to twenty logically separate HSMs, referred to as partitions. This can be field upgradable to up to 100 partitions per HSM. Keys stored within each partition are not just separated by thin access control lists, but are fully cryptographically isolated from every other partition. Partitions can be mapped to independent applications, assigned object limits per partition and, perhaps most importantly, can be controlled by a separate group of users. This feature is not only useful to utilities, but is also instrumental for device manufacturers. It provides the capability to run separate subordinate CAs at the factory for each end customer, tailoring the manufacturing of devices to specific customers. Through HSM partitioning, a device manufacturer can cryptographically isolate its customers so that a compromise of one customer does not impact other customers. It also enables the use of low-cost contract manufacturers without putting at risk securitysensitive customers who may not be able to accept devices manufactured in certain countries.
Meter Data Mgmt System
Head End Messaging
Code Signing
Key Manager
High Availability and Load Balancing
HSM Root of Trust
DR site for HSMs
PKI Root
Automatic Key Replication
HSM partitioning for support of multiple applications in the smart grid
HSM Key Usage Controls. Smart grid devices can be manufactured all over the world and, given the cost sensitivities; they are often manufactured in locations that have limited trust. SafeNet HSMs provide key usage controls that allow a remote authority to manage how often a particular key is used. With this capability, an organization can tightly control how many devices each contract manufacturer produces—preventing the production of fraudulent devices by manufacturing vendors.
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Remote Activation. It is important to ensure the right people are in control of key material. HSMs are not typically located in the same site as the highly trusted individuals responsible for protecting an organization’s integrity. SafeNet’s Remote PED capability allows these highly trusted individuals to control HSMs from anywhere in the world—saving the significant costs of sending trust holders to multiple remote locations. SafeNet’s M of N capability ensures that no single individual can compromise the keys within the HSM. PKI Bundle. SafeNet’s PKI bundling allows a single set of HSMs to protect root and intermediate CA keys with a pure keys-in-hardware approach, and provides secure key pair generation and private key loading capability for smart meters, communication hubs, and other grid devices. The PKI Bundle offering works with existing HSM infrastructure, offering a flexible and cost effective option, configurable depending on the required deployment model. ECC Integrated Encryption Standard. It’s becoming common to base smart grid secure messaging systems on the ECC integrated encryption standard. Deploying ECIES with Suite B curves provides high-assurance cryptography with minimal impact to the resources within the constrained devices typical of the Smart Grid. ECC is being used as the secure cryptographic messaging system between HSMs and other device end points in the Smart Grid infrastructure. SafeNet’s HSMs provide high-performance ECDSA and ECDH cryptographic services that enable solutions built around ECIES. Of course, SafeNet HSMs also offer highperformance RSA and AES services – providing support for any cryptographic system. Secure Shipping. While distributing HSMs to manufacturing or distribution sites, best practices dictate the need to mitigate possible compromises during shipping. Working with Multiple sites and potentially multiple operational owners of secure infrastructure devices can be very operationally expensive – Secure Shipping allows units to be commissioned in a secure central location, trusted during shipment, and trusted once deployed at distributed target location, with secure features that can offer central control and trust while minimizing operational costs. SafeNet HSMs provide a secure shipping capability that places the device in a cryptographic locked down state. When a device arrives at its destination, the device’s security authority is restored to an operational state and receives a cryptographic verification of the device’s internal integrity. True Keys In Hardware Management. SafeNet HSMs use a key management approach that ensures keys are never stored anywhere except inside your HSMs. This is the only way you can keep track, and audit of all copies of your keys. With SafeNet, every copy of a key always maps to a physical entity—one of your HSMs. SafeNet HSMs ensure your High Assurance endpoints within the Smart Grid infrastructure will be protected by an auditable trust anchor. And you won’t be limited by the hardware—a single SafeNet HSM can hold up to more than a 100,000 ECC keys. Availability, Reliability, and Scalability. The smart grid demands reliability and availability, and SafeNet HSMs deliver. The devices are built with high quality components, including the ability to replace failed power supplies and fans while in service. Furthermore, the HSMs can be grouped into high availability N+1 clusters that provide linear performance scaling. The clustering technology provides automatic key synchronization and allows for the reintroduction of failed or new units without service interruption. SafeNet HSMs have been evaluated by a 3rd party to offer 5 9’s availability uptime.
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