Abstract: A method of operating a data publishing device to distribute data content to receiving devices in a network and a method of operating a device to receive data content in a network, as well as devices performing the methods. In one aspect, a method comprises: receiving, from another device, data content that has been encrypted with a symmetric key shared with a trusted data content publisher device, requesting, from the trusted data content publisher device, a subset of the encrypted data content received from said another device in the network, and verifying whether the received subset of the encrypted data content matches a selected section of the encrypted data content received from said another device, wherein a match indicates that the encrypted data content received from said another device can be trusted.