What is an out-of-band communications plan for incident response, and what should it contain?
Glassbreak Team · Published 2026-07-24
Every incident-response plan has a communications section. Most of them share a silent assumption: that email, Slack, and the ticketing system will be up, and that the attacker isn't reading them. In the incidents that dominate carrier losses — ransomware and identity-plane compromise — both assumptions fail at once. That's why questionnaires and audits now ask the uncomfortable version of the question: how do you coordinate when your own systems are the casualty, or the surveillance channel? This page covers what a credible answer contains and gives you a one-page template.
The two failure modes the plan must survive
- Unavailability. Ransomware encrypts the infrastructure your comms ride on; an IdP outage locks everyone out of everything behind SSO simultaneously — including the tools you'd use to talk about the lockout.
- Compromise. In BEC and intrusion cases, the attacker reads the inbox or the Slack workspace during the response. Containment plans discussed in-band tell the attacker exactly which door you'll close next, and which ones you haven't found.
An out-of-band channel is one that neither failure touches: reachable without corporate credentials, and not readable by someone holding them.
What a credible plan contains
One page, five sections:
| Section | What to write down |
|---|---|
| The channel | The specific system used for incident coordination, and the fallback ordering (e.g., E2EE workspace → conference bridge → phone tree) |
| The roster | Who is on it — named responders plus external parties (vCISO, IR retainer, breach counsel) — and how the roster is kept current when people join and leave |
| Access | How each person reaches it with no corporate credentials: pre-enrolled devices, separate accounts, pre-registered personal endpoints. Enrollment happens before the incident |
| Activation | Who can declare the channel active and how members are summoned — ideally alerting to phones over voice/SMS with acknowledgment, so you know who got the message and can escalate past who didn't |
| The record | Where decisions get logged, and how the timeline can be exported afterward for the insurer, regulator, or post-incident review |
Three details separate plans that work from plans that exist:
- Pre-enrollment is the whole game. A channel responders join for the first time mid-incident, by clicking an invite in the email that's compromised, is not out-of-band. Enroll everyone during onboarding; verify reachability in every drill.
- Acknowledgment beats broadcast. "We posted in the channel" is not coordination. Delivery tracking — who confirmed, who didn't, and automatic escalation to the next tier — is.
- The record has to survive the incident. Decisions made off-system still need a timeline afterward. If the channel itself keeps an attributed, exportable log, the timeline writes itself.
Why ad-hoc Signal groups fail the written answer
Practitioners default to a personal-phones Signal group, and mid-incident it genuinely helps. As the documented control, it fails three ways: membership is unauditable (the contractor from last year is still in the group), delivery is best-effort (no acknowledgment, no escalation), and nothing is evidenceable (no roster, no log, no export). IR consultancies feel this acutely — they coordinate client incidents on personal messengers their own compliance narratives can't survive. The fix isn't abandoning E2EE messaging; it's using an E2EE channel that is also rostered, delivery-tracked, and logged.
How Glassbreak fits (and honest limits)
Glassbreak is a pre-staged out-of-band layer: end-to-end-encrypted chat and calls that don't depend on your IdP, alerting over voice, SMS, and email with acknowledgment tracking and escalation tiers, pre-enrolled emergency contacts, and attributed logs — alongside the quorum-gated break-glass credentials your responders will need on the same bad day. Honest limits: E2EE means we cannot read or recover your message content, and Glassbreak is not an insurer — this page describes the control, not a coverage guarantee. Test the whole path with a tabletop exercise; the IdP-down scenario specifically has its own first-hour checklist.
Frequently asked questions
- Why isn't our Slack incident channel enough?
- Two reasons. Availability: Slack sits behind your SSO — the outage or compromise that triggers the incident can take it down with everything else. Confidentiality: in an intrusion, assume the attacker can read anything reachable with stolen corporate credentials. Discussing containment in a channel the attacker may be watching hands them your response plan in real time. The out-of-band channel exists precisely so neither failure mode applies.
- Is a personal-phones Signal group an acceptable answer?
- It's better than nothing and common in practice — IR consultants run engagements this way daily. But as the written answer to a questionnaire or audit it has problems: membership is unmanaged (departed employees quietly keep access), delivery is best-effort (no acknowledgment or escalation), and there is no exportable record that the coordination happened. If a regulator or insurer asks for the incident timeline, "it was on someone's phone" is a bad sentence to say.
- What does "independent of the identity plane" mean concretely?
- Participants can reach the channel using credentials that do not depend on your IdP, SSO, or corporate password manager — separate accounts, pre-enrolled devices, or delivery to personal contact endpoints (phone, personal email) that were registered in advance. The test: if Okta/Entra and the corporate password manager were both unavailable right now, could every responder still join within minutes?
- Does Glassbreak replace our whole communications stack?
- No — it's the emergency lane, not the highway. Day-to-day work stays in your existing tools. Glassbreak provides the pre-staged out-of-band layer: E2EE chat and calls independent of your IdP, plus alerting over voice, SMS, and email with acknowledgment tracking and escalation — with the roster, delivery record, and logs that make the plan evidenceable.