In some embodiments, a verification service receives a description for a combination of a set of ranges within content available for download. The set of ranges are not sequentially located in the content that a client device has downloaded. The verification service determines if a first portion of the combination of the set of ranges has been received in a prior request. When the first portion has been received, the verification service retrieves a first set of verification values that represent subsets of content corresponding to the first portion. When at least a second portion of the combination of the set of ranges has not been received, the verification service generates a second set of verification values using subsets of content corresponding to the second portion. One or more of the first set of verification values and the second set of verification values are sent to the client device.