Abstract: The present systems and methods provide for secured communication between a mobile device and a server/gateway. The systems and methods can be used, for example, as a way to confirm whether or not a transaction was actually authorized by the user, thereby settling a chargeback dispute for a previously executed transaction. The method comprises receiving the dispute regarding the transaction including associated transaction data, and retrieving a digital signature associated with the transaction data, the digital signature computed by signing the transaction data. The digital signature is then verified using a public key, wherein the public key corresponds to a private key stored on a mobile device. It is then determined whether or not the transaction is fraudulent based on a verification result of the digital signature.