]> Federal University of Rio Grande do Sul

Porto Alegre Brazil lrsoares@inf.ufrgs.br

Federal University of Rio Grande do Sul

Porto Alegre Brazil jcnobre@inf.ufrgs.br

Green Networking Security With the advancement of the climate emergency, all areas of human activity are expected to continuously assess their Greenhouse Gas emissions and encourage the use of clean energy as much as possible. The current discussion on green networking in the Network Management research field still needs to be expanded to the adjoined areas, such as Network Security. This document outlines possible research directions for energy-aware security mechanisms.

Introduction Computer networking and the Internet are no exception to the global necessity of reducing CO2 emissions. Strategies to use energy efficiently can target the Internet backbone infrastructure, hardware components, protocols, and so on. Regardless of the approach, the green networking effort must follow from robust measurement frameworks capable of providing comprehensive visibility into the energy consumption of the network . Despite the advancements on green networking, much of the discussion still needs to be expanded to adjoined research fields, such as network security. Security protocols and applications are some of the more expensive, and are likely to show up in measurement tools as top consumers of energy resources. However, neglecting them in modern applications is simply not possible. Policies and guidelines must take functionality into account when regarding energy consumption, or risk compromising security algorithms. This document discusses the case for security protocols and applications to be regarded with special attention inside the green networking effort, and outlines future research directions for this goal.

Security Considerations in Green Networking In most of the works in green networking so far, the security considerations are mostly regarding extra attack surface brought by the energy measurement tools and controls. An attacker might use these mechanisms to put resources to sleep in critical moments, drain energy to cause damage such as overheating and battery loss, and to tamper with the energy measurement, which would cause misguided energy saving policies to be put in place. Though these are all important considerations, they are security risks for energy-saving mechanisms and not energy-saving considerations for security mechanisms.

Research Directions on Energy-Aware Security Mechanisms This document presents a non-exhaustive list of possible research challenges regarding the scope of security mechanisms in green networking. To illustrate possible outcomes of these research directions, we use the case of energy consumption of VPN protocols in Consumer-Premises Equipment (CPE) devices. In 2023, Netflix estimated that CPE devices accounted for roughly 38% of total carbon emissions of streaming service usage . VPN protocols can significantly increase both the processing load and the communication overhead of network devices, and consequently, their energy consumption. The purpose of this example is to discuss the research topics of the green networking area when it comes to security--this is an informational document and should not be regarded as a standard proposal of any kind.

Measurement and Benchmarking This research challenge borrows from the general state of affairs in the green networking research field, that is--datasets are needed if we want to make assumptions about energy consumption of protocols and applications. When it comes to security, what experimental setups we can use to assess the energy consumption of networking devices and security protocols, and what data they should collect? In our VPN-CPE use-case, we used a testbed with an ESP32 and an INA228 current/power monitor to monitor two MikroTik devices operating under varying traffic profiles. We collected the total energy consumed by the device operating under a set VPN protocol, and the total number of bytes successfully delivered during the same interval. We also measured the baseline of no VPN protocol. Other works benchmarking energy in network equipment are and .

Metrics in the Security Context Are the energy metrics used in the context of security applications and protocols any different from the regular traffic metrics from the general green networking field? Do they need to be? Security protocols and applications often have greater costs if compared with other networking protocols. Energy consumption metrics should take functionality into account to avoid compromising security properties. For example, we measured the energy cost of the CPE devices running each VPN protocol in millijoules per megabyte (mJ/MB). We then used the energy cost against the equipment's baseline of no VPN to compute a metric we called the Net Energy Cost of each protocol--that is, the energy cost beyond the idle operation. However, this method still raises some questions. How these metrics vary with protocol functionality? In other words, the Net Energy Cost of other network protocols will be lower than the VPN's, but this doesn't mean the VPN should be turned off to save energy. Even more importantly, are any of these metrics up for industry-wide standardization? The standardization effort of energy metrics in networking is a key step for energy awareness throughout the entire Internet. Solid standards can avoid proprietary, redundant, and even contradictory metrics from taking hold across different vendors .

Cost-benefit analysis When considering a security protocol or application, how can we assess if energy can be saved with little harm to safety and functionality? A fundamental aspect of risk-based security is that protocol selection should be guided by the needs of each deployment scenario, even before sustainability concerns come into consideration. However, there's a lack of visibility into the energy requirements of security protocols, which excludes the energy aspect from this cost-benefit analysis. Standard networking metrics such as throughput, jitter, and latency are well established--this should be the case for energy-efficiency metrics as well. In the VPN-CPE use-case scenario, each VPN protocol we tried had different cryptographic and security guarantees. Measuring the mentioned energy metrics revealed a trade-off between energy consumption, throughput, latency, and security properties--which would be helpful to a network operator designing the security architecture of a network or application.

Comparison from an energy perspective To be added.

Security Considerations To be added.

Sustainability Considerations To be added.

IANA Considerations To be added.

Acknowledgements We thank the sustain RG chairs for their comments on the original version of this draft.

Informative References Reducing humankind's environmental footprint and making technology more environmentally sustainable are among the biggest challenges of our age. Networks play an important part in this challenge. On one hand, they enable applications that help to reduce this footprint. On the other hand, they significantly contribute to this footprint themselves. Therefore, methods to make networking technology itself "greener" and to manage and operate networks in ways that reduce their environmental footprint without impacting their utility need to be explored. This document outlines a corresponding set of opportunities, along with associated research challenges, for networking technology in general and management technology in particular to become greener, i.e., more sustainable, with reduced greenhouse gas emissions and less negative impact on the environment. This document is a product of the Network Management Research Group (NMRG) of the Internet Research Task Force (IRTF). This document reflects the consensus of the research group. It is not a candidate for any level of Internet Standard and is published for informational purposes. Internet communications and applications have both environmental costs and benefits. The IAB ran an online workshop in December 2022 to explore and understand these impacts. The role of the workshop was to discuss the impacts and the evolving industry needs, and to identify areas for improvements and future work. A key goal of the workshop was to call further attention to the topic and bring together a diverse stakeholder community to discuss these issues. Note that this document is a report on the proceedings of the workshop. The views and positions documented in this report are those of the workshop participants and do not necessarily reflect IAB views and positions. n.d. n.d.

Changelog

• Replaces draft-soares-nmrg-green-security-00: the previous version was aimed at nmrg, since it was published before the creation of sustainability-specific groups such as sustain.
• Additional changes: parts of the text were re-written for clarity; each research direction was detailed and the VPN-CPE use-case was added as an example.