The post-quantum future of web privacy

The highest priorities for the transition to post-quantum cryptography are the basic building blocks of authenticated key-agreement protocols such as TLS. Without these building blocks in place, secure communication on the Internet will not be possible once cryptographically relevant quantum computers come online. However, today we rely on quantum-vulnerable cryptography for much more than TLS.

Privacy Pass is a protocol used by site operators like Cloudflare to help protect applications from abuse. One way we do this is by rate limiting individual clients so that no one client consumes too many of the site's resources. Normally this involves some combination of friction or loss of privacy for users: CAPTCHAs or other challenges to moderate traffic, along with accounts and fingerprinting to identify traffic.Privacy Pass was designed to avoid this tradeoff between friction and privacy. The basic idea is that a client gets issued a number of tokens, which they can redeem in exchange for access to the site. Crucially, each token is unlinkable to the client it was issued to, ensuring the client can use the site as they always had without sacrificing privacy.

With 10 years of deployment experience under our belts — using Privacy Pass for applications Continue reading

Scriptable GeoDNS: leaving AWS for Bunny

To optimize the performance metrics of this blog, I relied on Amazon CloudFront to serve the assets,1 and Route 53 for the geo-aware DNS2 to direct readers to the closest host serving the content. But Route 53 is expensive: US$0.50 per zone per month, US$0.70 per million geolocation queries, and US$0.75 per healthcheck per month, plus US$1 per month for the KMS key needed to sign zones with DNSSEC. When I discovered that Bunny DNS is almost free for up to 500 domains and features scriptable answers, I made the jump! Plus, it's a European company based in Slovenia.

Bunny CDN

Bunny.net started as BunnyCDN in 2015. They added IPv6 support in 2017. Switching was uneventful. I don't bring a custom domain: I serve the content from the b-cdn.net domain. As I depend on content negotiation to serve AVIF and WebP images, I configure the CDN to cache each image format separately.

I disable logging to avoid collecting personal information. While the bunny.net GDPR page promises they anonymize data, it is unclear what CloudFront keeps Continue reading

Agents aren’t humans (but they kinda are)

AI Agents now act on the web for millions of people. To a Site, an Agent can take many forms. It may be indistinguishable from a human user carrying out a task, or it might look like one visitor carrying many Users. This removes the ability for the Site to recognize, serve, and hold accountable the user or users behind the Agent, and causes the Site to face the costs when something goes wrong. This post argues that in order for Sites to maximize the access they provide to Agents, the ecosystem must develop new mechanisms to preserve the relationship between Sites and Users. Traditionally, in Security and Fraud Prevention, that requires three things: Identity, Reputation, and Accountability, allowing Sites to answer: Is the person acting being truthful about who they are? Is that person trustworthy? And who answers for the action?

“Personal AI Agents” (“Agents” for short) are automations that take instructions from a human (“User”) and pursue a goal by controlling a cloud computer or browser. They are usually hosted and maintained by an “Operator” as part of a managed service or consumer offering. Examples include Muse from Meta and dots from OpenAI, and more are launching all Continue reading

The Control Plane: BGP EVPN/VXLAN for AI Fabrics

This post discusses the application of BGP EVPN/VXLAN in AI data center networking, particularly focusing on back-end GPU fabrics. It emphasizes that single-tenant setups may not require VXLAN overlays, while multi-tenant environments benefit from logical segmentation. Key insights include the preference for Symmetric IRB over Asymmetric and the relevance of Type 5 routes for subnet aggregation.

The post The Control Plane: BGP EVPN/VXLAN for AI Fabrics appeared first on /overlaid.

See the agents, set the terms: new visibility and control for personal agents

Personal agents are the intermediary between humans and the Internet, turning a person’s instructions into requests and actions on websites. A customer might ask a personal agent to compare products across your site, find support articles, or complete a purchase. To a site owner, all three interactions show up as automated traffic — and without a clear view of which agents are visiting and what they are doing, it can be difficult to know whether that traffic is helping your business or creating risk. Blocking agents altogether can feel like the safest choice, but it can mean losing customers. Better visibility into agent activity allows you to decide what access makes sense for your site.

Today, we’re launching new analytics to help you understand how personal agents access your site on behalf of humans, along with more granular access policies to put those decisions into practice. Together, they let you welcome agents on your own terms, and in ways that support your business.

See how agents access your site

Knowing which agent is behind a request turns unexplained automated traffic into traffic you can act on with confidence. Cloudflare maintains the largest verified bot directory in the world, and we are Continue reading

Candidate and Active Configuration on IOS XR

Traditional network devices used a single (active or running) configuration, with a snapshot of it stored in permanent memory (startup configuration). The active configuration was modified with every configuration command, making it a perfect recipe for disaster in the days of in-band configuration1.

The situation improved drastically when Juniper introduced the candidate configuration. You could make changes to a copy of the configuration, and then commit them as a single all-or-nothing transaction. While you could still cut yourself off from the device, at least it was harder to do with a single misordered command.

Read more …

Detecting incast congestion of RDMA flows

The recently released open source GitHub project, ai-monitor, is a proof of concept demonstrating that real-time sFlow telemetry can detect and characterize incast RoCEv2 RDMA flow collisions between GPUs during AI training. 
docker run -p 6343:6343/udp -p 8008:8008 sflow/ai-monitor
The pre-built sflow/ai-monitor image is the quickest way to try out the software. The diagram at the top of this page shows test RDMA flows crossing a 4 leaf / 2 spine test network to generate an incast collision. The flows are displayed using the trace-flow application that is included in the image.

The ai-monitor application uses packet samples to detect when GPU port is oversubscribed:

  1. Detect when an leaf switch egress port utilization exceeds 80%
  2. Count the number of sources sending traffic to the port - single flows are ignored
  3. Trace each of the flows back across the topology to its source GPU

The instant the threshold is crossed, the following incast_congestion event is generated by querying information maintained within the sFlow-RT analytics engine. Real-time elephant flow monitoring in AI / ML fabrics describes how standard sFlow from data center switches streams real-time telemetry that can be used to detect elephant flows with a few milliseconds.

{
 "event":  Continue reading

Introducing Zero Wire, a hub for investigating critical Internet vulnerabilities

You run security at your organization. It’s 7:00 am, and you’re having breakfast. You receive a ping: a new critical vulnerability has been disclosed. Your team scrambles to compare vendor advisories, read technical research, check which systems run the affected software, and answer familiar questions from the business: are we affected, and what are we doing about it? Another disclosure arrives before that work is finished.

AI is changing both the volume and speed of critical vulnerability discovery. It can analyze large codebases at scale and surface deeply nested flaws that may have existed for years without being found through human review. That discovery momentum will put more pressure on security teams to understand the impact of each disclosure on their infrastructure.

To help security teams prepare, today we’re introducing Zero Wire: a public vulnerability intelligence feed on Cloudflare Radar, bringing the clarity of a news wire service to critical security developments. It helps security leaders and practitioners understand significant vulnerabilities and decide what to do next.

How it works

Zero Wire lives inside Cloudflare Radar under the security section.

Each briefing brings together a plain-language explanation of the vulnerability, who should investigate it, recommended actions, and links to Continue reading

Help Me Make the BGP Labs Even Better

I decided to add “Further Reading” sections to BGP lab exercises, containing links to vendor documentation and useful related blog posts. I naively expected to offload the job to Claude, commit the results, and move on. The “related blog posts” were a piece of cake; precise links to relevant vendor documentation turned out to be more of a challenge.

TL&DR: I would love to get your suggestions for further reading as PRs in the BGP Labs repo.

Apart from FRRouting, the vendor documentation is mostly generated from whatever internal system and uses auto-generated anchors that can change at any moment – somewhat “suboptimal” for what I wanted to do.

Read more …

What a ‘Kill Switch’ Actually Means for Your Agent Fleet

In short, in the five weeks to 27th October 2026, Okta, Satya Nadella, the Cloud Security Alliance and Salesforce each put the words “kill switch” or “emergency brake” next to AI agents, and the AI Kill Switch Act, introduced in the US House on 23rd July, would require the largest model providers to be able to throttle, suspend or shut their systems down on order. Every one of those switches stops something, and none of them stops the same thing. Pull the switch on an agent in your cluster and read what is still true a minute later: the Deployment has replaced the pod, the callers are retrying, the open sessions are still open, and the key in the agent’s environment still works. A kill switch for a fleet is a set of cuts at points the agent does not control, and the only way to know which ones you hold is to pull them. This post reads the bill and the UK NCSC’s advice for what a stop has to do, runs a drill through the five switches teams reach for, then says what a governance layer like Tigera Lynx can and cannot do about it. It is written Continue reading

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