A computing device may receive a file previously uploaded by another device, and may validate the received file using data including a first value encrypted based on a document (e.g., a digital certificate or identification certificate) of the uploading device. The computing device may determine the validity of the certificate based on a certificate of a remote computing device to which the file was uploaded, and may decrypt the first value using a key of the certificate of the uploading device. The computing device may determine a second value for the received file and may determine validity of the received file based on a match of the first value and the second value.