A cross-platform workflow is a product design where one account, task, or document can move across multiple devices and interfaces, such as phones, tablets, desktops, cars, and web apps. The goal is convenience and continuity: users can start an action on one surface and finish it on another without losing context.
In cyber security, this matters because every added surface becomes part of the attack surface. A workflow that spans devices must keep authentication, session state, permissions, and content handling consistent across very different environments. Weaknesses can appear as token theft, insecure device linking, overexposed data in low-friction interfaces, or unsafe file processing when documents are edited or rendered inside the app. Defenses usually include least-privilege access, strong session binding, secure handoff between devices, input validation, and tight control over what each interface can display or modify. Cross-platform workflows are useful, but they require security review whenever a product expands into a new environment.