1. A computer-implemented method comprising: a) accepting, by a payload attribution system, a payload content and attribute information of a flow; b) segmenting, by the payload attribution system, the payload content into a first set of blocks; c) for each of the blocks of the first set of blocks, generating, by the payload attribution system, a summary of each of (1) the block, (2) the block together with corresponding offset information, and (3) the block together with the corresponding offset information and the attribute information of the flow, using at least one summarizing function; and d) storing, by the payload attribution system, for each of the blocks of the first set of blocks, the generated summaries on a computer-readable storage device.