# Blockchain interaction In Sealed, interaction with Algorand is protected by OHTTP. This matters because the app needs to communicate with blockchain infrastructure to send and retrieve encrypted messages, but the RPC provider should not directly see the user’s IP address. OHTTP adds a privacy layer between the user’s device and the RPC endpoint. It allows Sealed to use public blockchain infrastructure while reducing the network-level metadata created during normal app usage. ### What OHTTP is OHTTP stands for Oblivious HTTP. In simple terms, it is a way to send a request so that the service processing it does not directly know who originally sent it. In a regular connection, the service receiving a request can usually see both the request itself and the IP address of the device that sent it. With OHTTP, this information is separated. The RPC endpoint can process the request, but it does not directly receive the user’s IP address. ### Where Sealed uses OHTTP Sealed uses OHTTP when the app interacts with the official Algorand RPC. This applies to the blockchain operations needed for normal messaging, such as submitting encrypted message data and checking the chain for messages that may belong to the user. This protection is part of the app’s default connection flow. The user does not need to manually set up a VPN, proxy, custom node, or special network configuration. ### What OHTTP protects OHTTP protects the network identity of the device during RPC communication. The main thing it hides from the RPC layer is the user’s IP address. This is important because an IP address can reveal approximate location, internet provider, network type, and activity patterns. Without OHTTP, the RPC provider could potentially connect blockchain requests with the device or network that made them. ### What OHTTP does not hide OHTTP protects the connection between the user and the RPC layer, but it does not make public blockchain activity disappear. Transactions and encrypted message data that are placed on-chain remain visible as blockchain activity. This distinction is important. OHTTP protects the network path. Encryption protects the message content. The smart contract design helps reduce direct sender-recipient links. These are separate privacy layers that work together. ### User benefit For the user, the benefit is that Sealed can interact with Algorand without directly exposing the device’s IP address to the RPC provider. Sending and receiving messages still feels like using a normal app, while OHTTP works quietly in the background. --- # 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.sealed.channel/security-and-privacy/blockchain-interaction.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.