The Gap Sentinel Closes

Modern identity and access architectures implicitly assume that once a user successfully authenticates, the device and session remain under that user’s control. In reality, there is no assurance that the authenticated user remains physically present or in proximity to the access device from the moment intent is expressed through the end of the session. Shared workspaces, remote access, session hijacking, unattended terminals, and post-authentication misuse all exploit this blind spot.

Existing authentication and session management technologies do not measure or enforce user-to-device proximity, nor do they provide continuous, policy-driven signals that can be acted upon without redesigning the access stack. As a result, organizations lack visibility and enforcement during the critical gap between login initiation and session termination—precisely when attackers take advantage of implicit trust.

Sentinel closes this gap by continuously asserting user and device proximity throughout the session, enabling real-time monitoring and enforcement without rearchitecting existing systems.

It effectively solves the "Coffee Shop Problem"—where a user authenticates and then walks away from an active session, leaving it vulnerable to unauthorized use. By adding Sentinel, you are moving from Point-in-Time Authentication to Continuous Presence Assurance.

What Sentinel Does

When a user first indicates an intent to initiate a login ceremony, Sentinel begins actively verifying the physical proximity of the user’s cell phone to the access device. It continues this proximity verification at a policy-defined cadence for the duration of the session. Sentinel produces continuous metrics that indicate user and device proximity, then transmitted to the API service and forwarded from there to monitoring and enforcement authorities. This active, policy-driven reporting enables real-time visibility and enforcement throughout the otherwise unprotected gap between user intent to login and session termination.

Why Sentinel Matters — Use Case Examples

Unattended or Walk-Away Sessions

A user authenticates successfully and steps away from their workstation, leaving an active session behind. Sentinel detects loss of phone proximity and provides a real-time signal that can trigger session lock, step-up verification, or termination—reducing exposure from unattended access.

Session Hijacking After Authentication

An attacker gains control of a device or session after the login ceremony completes. While traditional controls remain blind, Sentinel continues validating user presence, enabling detection and enforcement when the authenticated user is no longer physically present.

Shared and High-Risk Workstations

In environments such as healthcare, manufacturing, trading floors, or call centers, devices are frequently shared. Sentinel ensures that access persists only while the authenticated user remains in proximity, enforcing accountability without repeated logins.

Remote Access and Privileged Sessions

Privileged users often maintain long-lived remote sessions that become high-value targets. Sentinel provides continuous proximity assurance throughout the session, supplying monitoring systems with signals that can enforce tighter controls on elevated access.

Compliance-Driven Access Enforcement

Regulatory and internal policies may require proof of user presence during sensitive operations. Sentinel supplies continuous, auditable proximity metrics that support compliance, monitoring, and incident response without redesigning authentication flows.

Zero Trust Session Assurance

Zero Trust assumes no implicit trust, yet most systems trust the session once established. Sentinel operationalizes Zero Trust principles by continuously validating user presence from intent through session end, enabling adaptive, policy-based enforcement.