# Overview While inscriptions based on Ordinals or other protocols are emerging in the Bitcoin ecosystem, they are intended for tradable assets rather than identity that is non-transferable by nature. We propose a new protocol to implement ***Soulbound Tokens(SBTs)*** where the ownership is not transferable once granted. As the important feature, privacy mechanisms including ***commitment*** and ***zero-knowledge proof*** are integrated into the protocol to support private identities. The protocol is built on top of Taproot and aimed to be the ***SBTs-based Identity Layer*** for Bitcoin. --- # 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://btc-sbt.gitbook.io/btc-sbt-protocol/overview.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.