Can Blazor WebAssembly reliably verify restored state after Service Worker cache rebuild?

Goal: Restore and verify component state

When a Blazor WebAssembly app is installed as a PWA and the Service Worker cache is rebuilt—due, for example, to an update or a manual cache purge—developers need to ensure that any data persisted in localStorage or sessionStorage remains intact and reflects the latest application state.

Constraints and Uncertainty

• Dynamic API responses are not automatically cached; developers must decide whether to store JSON payloads locally.
• Local storage capacity is limited, and data may be cleared by the browser or the user.
• Blazor does not provide a built‑in hash function to verify persisted state.
• Asynchronous storage access can introduce race conditions during restoration.

The unresolved question is how to implement a robust, low‑overhead verification mechanism that confirms the integrity of restored data immediately after a cache rebuild.

Specific Questions

1. Which hashing strategy (e.g., SHA‑256 via Web Crypto API) is most suitable for validating complex component state stored in localStorage?
2. How can developers detect and respond to a hash mismatch when the app starts after a Service Worker cache rebuild?
3. Is there a recommended pattern for conditionally re‑fetching stale data when verification fails, without compromising the offline user experience?