I write app for Android which will be communicate with HTTP server. I need to ensure that data will be provided to server without any changes. If any changes occured during the transmission I need to retransmit data. I know that TCP have it's own mechanism of checksum, and here is my question. Do I need to implement my own checksum system or maybe TCP checksum will enough?
Use HTTPS instead of HTTP. HTTPS adds a message authentication code to each record transferred, which guarantees data integrity. This protects against accidental damage during transmission, and also against tampering by an attacker.