COMMENTARY: In December 2025, San Francisco became the stage for a modern technological paradox: Responding to a local power outage, a fleet of Waymo autonomous vehicles came to a grinding halt, creating a freeze that rippled through the city.On paper, the system worked perfectly. The vehicles were digitally secure, they weren’t compromised by a malicious actor and they followed their programmed safety protocols to the letter. Yet, in the physical world, they created a massive infrastructure failure, blocking emergency responders and paralyzing public transit.[SC Media Perspectives columns are written by a trusted community of SC Media cybersecurity subject matter experts. Read more Perspectives here.]The incident serves as a wake-up call for the cybersecurity industry, revealing that we have reached a tipping point of cryptographic debt. For the last decade, we have focused almost exclusively on securing the identity of devices – ensuring we know exactly who or what machines are. But in doing so, we have dangerously neglected their operational continuity. To prevent the next freeze, we must move beyond static identity and toward a more resilient, dynamic continuum of trust.
The trap of static identity
Traditionally, we have relied on public key infrastructure (PKI) to deliver a "digital handshake." This handshake establishes a foundation of trust, but it’s inherently static. Once a device gets authenticated and "trusted," the industry has largely assumed it will continue to behave correctly. The San Francisco outage exposed the flaw in this logic: traditional PKI doesn't offer instructions for when that handshake gets broken. When these vehicles encountered a variable they couldn't process, such as traffic signals that shut down, they defaulted to a "fail-safe" mode. In a vacuum, stopping is safe. In an urban ecosystem, a fleet of unmovable objects becomes a hazard.We need to evolve toward systems that don't just ask: "Who are you?" We need architectures that constantly evaluate, "What are you authorized to do right now in this specific context?" This shift from static identity to dynamic, context-aware authorization is the only way to ensure safety in environments where human lives are on the line.High stakes of operational continuity
The lessons learned in San Francisco extend far beyond the automotive sector. As we integrate autonomous systems into the backbone of our society, the identity-only model creates systemic risks across other high-stakes verticals. Consider situations such as:- Remote surgical robotics: In a telesurgery environment, a momentary loss of cloud connectivity cannot result in a "freeze" of the instrument. The system must have the local cryptographic authority to continue the procedure safely without a continuous back-end handshake.
- Smart grid infrastructure: Automated distribution switches must balance load-leveling with emergency overrides. If an outage occurs, these devices cannot wait for a centralized "all-clear" if the communication lines are down; they must have pre-validated, local trust protocols to prevent a total grid collapse.
- Automated logistics and warehousing: In massive fulfillment centers, dozens of heavy machines coordinate movements in high-speed choreography. If the facility’s local network dips, these machines must have the intelligence to avoid collisions and find a safe egress without a central "brain" to guide them.
