This document discusses ensuring data integrity for data stored in the cloud. It proposes using a combination of the Station-to-Station key exchange protocol, XOR encryption, and SHA-2 hashing to verify integrity with a third party auditor. Specifically, the Station-to-Station protocol generates a shared secret key for the user and auditor. The user XORs their data with the key before storing it. To audit, the auditor retrieves the encrypted data, XORs it with the key to decrypt it, then hashes the decrypted data and compares the hash to the user's original hash to verify integrity. This allows a third party to efficiently audit the integrity of outsourced data without accessing the raw data.