# FAQ ## General **Q:** **How does PW protect users' privacy?** A: PhalaWorld can only access user data via the address connected, while ID graph addresses remain undisclosed to the public. The MCP exclusively returns user-authorized, aggregated identity data to PW, with ID graph addresses being privately safeguarded. In essence, PW has no means of knowing a user's DID account beyond the connected address and data returned by MCP. The user's ID graph is currently stored on MCP servers. MCP does not monitor user on-chain activity or store data other than the ID graph. It serves as an off-chain version of Litentry's aggregated identity. Once the Litentry aggregated identity blockchain gets developed, MCP will transition to a decentralized model, achieving a truly trustless, privacy-preserving aggregated identity. Linking to a specific platform is not obligatory; users should connect when they feel it's secure. If there are concerns about exposure during the account linking process, users can promptly remove any relevant information on platforms like Twitter or Discord following the post. **Q: Where can I buy $PHA and which wallet would I need to transfer to?** A: You can buy $PHA on Kraken (0.07 $PHA transaction costs) or Kucoin (10 $PHA transaction costs) and transfer the $PHA token to Phala Network. You can use Polkadot.js, Talisman, or Subwallet. See also this document for more options: **Q: I have $PHA tokens on the Ethereum wallet (ERC-20), can I bridge them to Khala?** A: Yes, please use SubBridge (), please be aware of the high fees that may occur. **Q: How can I trade the Shell NFT?** A: In the marketplace: . You need to use k-PHA. ## Spirit NFT related **Q: Will the attribute change after changing my Discord username?** A: You need to re-link your Discord account in MCP platform, then update the attribute, and it will be synchronized accordingly. --- # 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://docs.phala.world/introduction/faq.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.