Mitsuru Kanda

A key management framework for AMI networks in smart grid

The environments in which current electric grids operate as well as the requirements for the emerging smart grid differ substantially from those of todays Internet and telecommunication networks. For example, typical electric or gas meters in the advanced metering infrastructure (AMI) are low-power, low-capability wireless devices utilizing personal area wireless network technology (e.g., IEEE 802.15.4). These devices are low-cost, typically with 4-12 kbytes of RAM and 64-256 kbytes of flash memory, and are often connected to the backhaul via low-bandwidth links. Comparing this to the high-powered, high-capability devices of the Internet with gigabytes of RAM and storage, the differences are striking. Security solutions designed for capability-rich Internet devices will not be suitable for the capability-poor devices of the smart grid; thus, new requirements are needed that can efficiently operate in resource constrained devices. With this operating environment in mind, we present a smart grid key management framework with application to AMI networks. Specifically, we describe how this key management model can be realized in such a resource-constrained environment using existing standard protocols and provide preliminary performance results.

Keeping clock accuracy on a master clock failure in substation network

Substation automation requires 4 µs accuracy and high availability of the clock synchronization mechanism. The clock synchronization protocol IEEE1588 satisfies the accuracy requirement under normal operation, but a failure on a grandmaster clock causes a large time error on the slave due to transient response by feedback loop. The failure may also trigger another failure on another grandmaster clock since IEEE1588 defines communication among them. We propose a new network architecture that utilizes IEEE802.1Q VLAN so that all grandmaster clocks can be in hot stand-by. The slave can simultaneously synchronize to and can switch between them without time error. Our proposal can also limit the impact of the failure on the other grandmaster clocks. We also describe the internal design of the slave, which consists of software of redundant feedback loops and a single oscillator. The experimental results show that the slave can keep time error under 70ns while a grandmaster clock is disconnected and the slave switches to another grandmaster clock.

USAGI IPv6 IPsec development for Linux

USAGI project was founded to improve and develop Linux IPv6 stack. We also developed (IPv6) IPsec stack for Linux kernel 2.4 and 2.6 series. We present our (IPv6) IPsec implementation (PE KEY, IPsec security association, security policy, output processing, and input processing) for both 2.4 and 2.6.

A security architecture for communication between smart meters and HAN devices

ECHONET Lite is recognized as a promising HAN protocol in Japan to be used as the standard interface for HEMS. On the other hand, detailed security architecture for HEMS based on ECHONET Lite has been missing. We propose and evaluate a security architecture for communications between HAN devices and smart meters. The proposed security architecture integrates HAN device registration and enrollment processes into a single network access authentication procedure using a tunneling EAP method. As a result of the evaluation, our security architecture is realized with less implementation effort to smart meters.

An Authentication Client Proxy mechanism for resource-constrained devices

The recent growth of Smart Grid and energy services introduced resource-constrained Internet communications devices such as smart meters, consumer electric devices, sensors, lighting devices and so on. In this paper, we propose a new proxy scheme designed for authentication and key establishment protocols for authenticating resource-constrained end-devices. The proposed scheme leverages key hierarchy in a way that the end-device can delegate the main protocol tasks of authentication and key establishment to the proxy and only a cryptographic and key management module including the root key of the key hierarchy needs to be retained by the end-device. The proposed scheme can reduce 70% and 28% of persistent storage for Class 1 and Class 2 memory-constrained devices, respectively. Also, the total memory reduction effect in the system consisting of a single proxy and multiple end-devices increases as the number of end-devices connected to one proxy increases.