公开(公告)号：US20170373856A1

公开(公告)日：2017-12-28

申请号：US15624544

申请日：2017-06-15

Applicant: Avast Software s.r.o.

Inventor： Antonín Kriz

IPC: H04L9/32

CPC classification number: H04L9/3242 ,  H04L9/0643 ,  H04L9/3247

Abstract: A system and method for prefix fingerprints for a first file or a first data object. A prefix fingerprint comprises a plurality of hash values. The hash values of the prefix fingerprints are typically generated starting at the same offset within the file or data object, but are generated based on different data sizes. Later, a second file or second data object can be compared with the first file or first data object to determine if the second file or data object is a prefix of the first file or data object. A hash value is selected from the previously determined prefix fingerprint of the first file based on the size of the second file. A hash is generated for the second file using the same offset value and size as was used to generate the selected hash value from the prefix fingerprint. The hash values are then compared.