Embodiments of the present disclosure provide a method, a device and a computer program product for data protection. According to embodiments of the present disclosure, a client receives, from a server, a certificate for verifying data validity. In response to receiving, from the server, an installation package to be verified for data validity, the client determines whether the installation package is valid using the certificate. The installation package is associated with one update application of the operating system of the client. In response to determining that the installation package is valid, the installation package is installed at the client.