CATALINK

Preventing the onset or escalation of conflict by building a resilient global communications system.

The Problem

Today’s nuclear command control and communications systems (NC3) rely on both legacy and modern technologies that are increasingly vulnerable to rapidly emerging, disruptive capabilities. This fact compounds what is already an untenable reality of NC3 systems: the communications links that underwrite their credibility are the first targets in any escalating kinetic conflict. Despite these facts, if and when NC3 systems fail under stress, leaders must still be able to communicate to prevent large-scale conflagration.

The Solution

An internationally-driven, secure, resilient communications solution that has the potential to avert catastrophes amidst rising tensions between adversaries: The CATALINK system.

The system ⁠consists of an endpoint device called a Puck that rides on a global mesh-network called the ROCCS⁠. The CATALINK would build on the “hotline” model of previous generations, and rely on internationally driven open-source technologies to maximize user integrity and trust. It would exploit redundant transmission capabilities to ensure that multiple parties could connect under extreme conditions, including loss of power and the absence of cellular and/or internet connectivity. Endpoint devices would be designed for durability, availability, and ease of use, enabling parties to immediately connect with confidence amid crises. These endpoint devices would also be secure: the firmware, software, and hardware would all meet cutting edge world class requirements for security. Looking for examples of how to build international consensus around this concept, we took inspiration from the process that led to the creation of the National Institute of Standard and Technology Advanced Encryption Standard (NIST AES). To ensure the integrity and validity of the technical solution, we are building a community of passionate global citizens from varying professional backgrounds.

The Puck: A simple, secure and robust device meant for dedicated communication between global leaders and officials during a nuclear crisis or other high-stakes events like disaster response. The Puck project consists of designing, developing and supplying the PUCK Platform board based on open-source platform design, to include consideration and agreement for applicable hardware (RISC-V), firmware (OREBOOT) and software.

ROCCS: Resilient Omni Frequency Crisis Communications System based in a global mesh network. ROCCS is a permanently active network that utilizes multiple networks and channels/wavelengths to ensure reliable relays of Puck messages and is one of a variety of redundant networks on which the Puck messages may ride depending on availability, the threat environment, and the type of message sent. Between the ROCCS and the Puck exists a “Broker” interface, which determines the path of the Puck message throughout the desired network. The Broker will switch networks as needed – including between satellites, commercial networks, fiber-optic lines, and high-frequency or low-frequency radio bands – and will switch to the final resilient mesh network of the ROCCS if/when all other options fail or are compromised. ROCCS recognizes and works to integrate the need for leaders to communicate in a crisis where all conditions are degraded by conflict including the effects of nuclear weapons on the atmosphere, cyber attacks, electromagnetic jamming, and perhaps even biological attacks.

Securing the Signal: Mitigation Strategies to Strengthen Crisis Communication Channels
As global norms are challenged and emerging technologies accelerate, crisis communication systems between nuclear-armed states face urgent new threats. Designed to prevent escalation, these channels are increasingly vulnerable to both cyber attacks and diplomatic misuse. This report identifies four critical scenarios, and outlines a matched set of mitigation strategies designed to reinforce the reliability of crisis communications in high-stakes environments.
May 2025 | Report

Strengthening Nuclear Crisis Communications: Steps to Implement Mesh Networks to Enhance Resilience & Security
To advance work on secure crisis communications, IST convened a diverse group of experts for a technical workshop to explore potential avenues for improving the resilience of nuclear crisis communications networks, including IST’s #CATALINK Initiative. In this report, IST Senior Analyst for Defense & Technology Policy Christian Steins shares critical takeaways from their discussion. 
May 2025 | Report

Live at the United Nations: IST Joins Forces with Germany and Switzerland to Push for Progress on Nuclear Risk Reduction
At NPTPrepCom, IST and the Vienna Center for Disarmament and Non-Proliferation hosted a dialogue on preventing and managing nuclear crises sponsored by key #CATALINK supporters, the German Federal Foreign Office and the Swiss Federal Department of Foreign Affairs.
May 2025 | Blog

Improving Nuclear Hotlines: Experts Speak
In June, IST released a series of reports on nuclear crisis communications titled Improving Nuclear Hotlines: Relevance and Use Cases. These reports sought to answer the question: when or at what point in time, before or during a crisis, would states want to use a multilateral or bilateral crisis communications mechanism? On Thursday, July 18, report authors Dr. Manpreet Sethi, Dr. Rabia Akhtar, Dmitry Stefanovich, and Daniil Zhukov joined a virtual conversation moderated by IST Deputy Director of Nuclear Policy Sylvia Mishra, with an introduction by Technology Policy Analyst Christian Steins. 
Event | July 2024

Resilient Nuclear Crisis Communications: India’s Experience
Dr. Manpreet Sethi (Center for Air Power Studies) examines the outcome of historical uses of both military and civil hotlines among India and Pakistan. Part of the Improving Nuclear Hotlines series.
Report | June 2024

Pakistan: Mitigating Nuclear Risks Through Crisis Communications
Dr. Rabia Akhtar (University of Lahore) unpacks the India-Pakistan dyad from the perspective of Pakistan. Part of the Improving Nuclear Hotlines series.
Report | June 2024

Use-Cases of Resilient Nuclear Crisis Communications: A View from Russia
Dmitry Stefanovich (Center for International Security at the Primakov National Research Institute of World Economy and International Relations of the Russian Academy of Sciences) delves into resilient nuclear crisis communications from the Russian perspective. Part of the Improving Nuclear Hotlines series.
Report | June 2024

China: Nuclear Crisis Communications and Risk Reduction
IST’s Sylvia Mishra interviews Dr. Tong Zhao (Carnegie Endowment for International Peace) for his take on crisis communications in the People’s Republic of China. Part of the Improving Nuclear Hotlines series.
Report | June 2024

The Phone-a-Friend Option: Use Cases for a US-UK-French Crisis Communication Channel
Daniil Zhukov (King’s College, London) makes the case for a multilateral crisis communication channel between the heads of state of the United States, the United Kingdom, and France. Part of the Improving Nuclear Hotlines series.
Report | June 2024

Effects of Electromagnetic Pulses on Communication Infrastructure: An IST Primer
This primer details the effects of a nuclear detonation on communication devices, infrastructure, and networks to highlight the capabilities needed in an additive technical solution for international crisis communications. It focuses on the electromagnetic interference, specifically electromagnetic pulses (EMPs) and associated radiation, generated by a nuclear detonation.
Primer | January 2024

IST Launches New Crisis Communications Resilience Working Group
IST in 2023 announced the establishment of the Crisis Communications Resilience Working Group, a new effort to augment nuclear risk reduction efforts and promote effective, secure, multilateral crisis communications among nuclear-armed states. The Working Group (WG) consists of scholars, academics, practitioners, and technical experts from across Europe, Asia, and North America. 
Blog | October 2023

Nuclear Crisis Communications: Mapping Risk Reduction Implementation Pathways
Over the past few years, an international consensus has been converging on nuclear risk reduction, and tangible implementation proposals have focused on nuclear crisis communications systems. In this report, IST’s Sylvia Mishra underlines the importance of nuclear risk reduction and the growing need for modern crisis communications, identifying two scalable pathways to a crisis communications system.
Report | January 2023

hotline room

Nuclear Risk Reduction: In Search of a Common Denominator
As global nuclear dangers rise, risk reduction efforts through effective crisis communications are more important than ever. Yet differences in constituencies, priorities, and strategic cultures of nuclear weapons states generate disagreement as to which measures genuinely reduce risk. In December, IST hosted the webinar Averting Catastrophe: Walking the Talk on Nuclear Risk Reduction and Crisis Communication, which showcased the degree to which the American nuclear crisis communications playbook draws on its Cold War relationship with the Soviet Union, and how misaligned that playbook is with the contemporary relationship with Beijing.
Blog | December 2022

Averting Catastrophe: Walking the Talk on Nuclear Risk Reduction & Crisis Communication
Although most states agree that the need for nuclear risk reduction is more urgent than ever, the pathways to peace are elusive. This webinar explored some of the tangible risk reduction measures that states can adopt with Dr. Tong Zhao, Visiting Research Scholar in the Program on Science and Global Security at Princeton University; Dr. Todd Sechser, Professor of Politics and Public Policy at the University of Virginia; and Dmitry Stefanovich, Research Fellow at the Primakov Institute of World Economy and International Relations, moderated by Leah Walker, Senior Defense Associate at IST.
Event | November 2022

Playing Telephone: Hoax Calls and the Insecurity of Leader to Leader Communications
The fact that prank calls occur at all (and do so fairly often) reveals a clear lack of secure leader to leader communications and suggests the possible non-trivial exploitations of that fact. That there are not more secure mechanisms and procedures in place for these sensitive conversations ought to be of utmost concern.
Report | July 2022

Nuclear Hotlines: Origins, Evolution, Applications
This paper by Dr. Steven E. Miller gives an overview of experiences to-date with nuclear hotlines. It reviews the history of the US-Russia hotline, describes the ways that hotlines can be used or misused, and charts how the hotline concept has evolved and propagated to help states manage international crises. The paper shows hotlines as important, if imperfect, tools for avoiding nuclear conflict.
Report | October 2020

Last Chance: Communicating at the Nuclear Brink
This report, the product of a workshop hosted by IST and the Nautilus Institute, outlines a vision for a novel “hotline” system that would enable secure and verifiable communications between leaders during nuclear crises and other high-stakes scenarios.
Workshop Synthesis Report | May 2020

The Nuclear Risk Reduction Approach: A Useful Path Forward for Crisis Mitigation
In her article for Asia-Pacific Leadership Network, IST’s Sylvia Mishra highlights the importance of advancing the nuclear risk reduction approach and explains why IST’s CATALINK Initiative should be incorporated as a component of such an approach.
January 27, 2023 | IST in the News

The United States and China Still Need to Talk About Nuclear Weapons
The two countries “must return to talks at the earliest available opportunity to discuss their shared responsibility to reduce the risk of nuclear war through crisis management and arms control,” writes Sahil Shah in an op-ed for Foreign Policy.
February 6, 2023 | IST in the News

Philip Reiner on Nuclear Command, Control, and Communications
“What’s interesting about NC3 is that…where you can actually show that your systems are reliable and resilient and that they do the things they’re supposed to do, that is actually inherently stabilizing,” Philip Reiner tells Gus Docker. 
October 6, 2022 | IST in the News

Zoom Won’t Stop a Nuclear War
In an op-ed for Foreign Policy, Sahil Shah and Leah Walker outline why nuclear-armed states must rethink crisis communication technology and upgrade current hotlines, especially at the leader level, through a multilateral approach.
April 19, 2021 | IST in the News

Back Story with Dana Lewis: Nuclear Hotlines
“We feel we’ve struck upon something that could add value, not only from a technical perspective and give people tools that they could build off of, but also something that could be used at the diplomatic level as potentially a way to create trusted discussions and collaborative endeavors,” says Philip Reiner. Former British Rear Admiral John Gower outlines the set of questions that CATALINK could address: “Do you know who the person is at the other end of the phone? Can you be certain that they are the leader of that particular nation? Can you have a conversation with them with other leaders of directly-involved nations? And can you have such a conversation within all levels of disaster?”
March 3, 2021 | IST in the News

Press the Button: Strategic Stability
Sahil Shah joined Ploughshare Fund’s podcast Press the Button to talk strategic stability, transatlantic relations, and the need for reliable communications links in all nuclear contexts.
October 12, 2021 | IST in the News

Get Involved

The CATALINK project is a collaborative effort between our civil society partners, industry colleagues, and government officials from around the world. It is a proactively open process, and success requires active engagement with partners all around the world. If you are interested in joining in our efforts, please email [email protected] with your background, area of focus, and a detailed description of your interest in this work.

The CATALINK Initiative is supported in part by the Swiss Federal Department of Foreign Affairs and the German Federal Foreign Office.

Announcing Continued Support from the Swiss Federal Department of Foreign Affairs and the German Federal Foreign Office for the CATALINK Initiative
Over the last 3 years, the Swiss Federal Department of Foreign Affairs (FDFA) and the German Federal Foreign Office (AA) have been critical partners to the Institute for Security and Technology’s Innovation and Catastrophic Risk team in reducing nuclear risks through the development and implementation of the CATALINK concept. IST is pleased to announce the generous continued financial and political support from the Swiss and German governments through 2027.
Announcement | January 2025

The German Federal Foreign Office Commits Support to the Institute for Security and Technology’s CATALINK Initiative
The German Federal Foreign Office has generously provided a new grant in support for the Institute for Security and Technology’s CATALINK initiative. This funding will allow the organization to expand its work designing solutions to enhance the security of the global commons.
Announcement | July 2022

Resources

  • The GitHub page n2vi/hotline, owned by Eric Grosse, provides a proof-of-concept exploration of the CATALINK system architecture. Though still a long way from a product ready for real-world use, it contains working code that has actually exchanged a few messages. The code is transparent and functional; it is mainly intended to provide a basis for discussing possible approaches to then be more professionally created by an international technical team.
  • Nuclear weapons decision-making under technological complexity: This ELN report draws on the insights from former high-level nuclear decision-makers and current officials at a January 2021 virtual pilot workshop, held in cooperation with the Oracle Partnership. Based upon a “worst-case scenario,” the event explored the possible impact of predominantly aggregate technologies on nuclear weapon decision-making. It initiated one of four working strands which form a broader project on new technologies and nuclear decision-making undertaken by the ELN.
  • The Nuclear Crisis Group NATO-Russia Crisis Brief features recommendations from Rear Admiral John Gower and highlights IST’s CATALINK project as a modern, robustly encrypted, and survivable omnilateral solution.