# Why Existing Approaches Fall Short Several projects have attempted to put blockchain into the IoT stack. The vast majority of them fail at one of two predictable hurdles. **Hurdle:** the device cannot afford to be a blockchain client. A microcontroller with 512 KB of flash and an intermittent radio link cannot run a light client, cannot maintain a wallet securely, and cannot tolerate the latency of on-chain confirmation in its critical control path. TaτsuOS is engineered specifically to clear these hurdles. The device never speaks to the chain directly; it does not need to. And the off-chain backend is not trusted — it is merely a courier. The cryptographic root of trust is a public key compiled into the device's firmware, and the only entity that can produce a receipt that key will accept is whoever holds the corresponding private key. That key, in production, lives in a hardware security module. The result is an architecture in which the chain is the source of truth for what was paid, the firmware is the source of truth for what is permitted, and the cloud is, at most, a delivery mechanism that no party — including the operator — needs to trust. --- # Agent Instructions: Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter: ``` GET https://tatsu.gitbook.io/tatsu-whitepaper/why-existing-approaches-fall-short.md?ask= ``` The question should be specific, self-contained, and written in natural language. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.