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Information Technology LaboratorySoftware and Systems Division

## Software Quality Group

-  National Software Reference Library (NSRL)  Expand or Collapse    -  Curated Kaspersky Hash Set - 2017 
  -  About the NSRL  Expand or Collapse      -  NSRL Introduction 
    -  Library Contents 
    -  NSRL Frequently Asked Questions 
  -  NSRL Download  Expand or Collapse      -  Current RDS Hash Sets 
    -  Non-RDS Hash Sets 
    -  RDS Query Tools 
    -  NSRL Legacy Tool Downloads 
  -  NSRL Subprojects  Expand or Collapse      -  Diskprints 
    -  NSRL Unique File Corpus 
    -  NSRL and Voting System Software 
  -  Technical Information  Expand or Collapse      -  Approximate Matching 
    -  DFXML Schema 
    -  NSRL Presentations 
    -  NSRL Technical Papers 
  -  Subscribe  Expand or Collapse      -  NSRL Subscription Information 
    -  Redistribution Policy for NIST NSRL RDS 
    -  NSRL RDS Distribution Schedule 
  -  Contact Information 
  -  NSRL Partner Projects 
  -  NSRL Acknowledgements 

# NSRL Unique File Corpus

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 The NSRL keeps one copy of each unique (as defined by a SHA-1 hash string) file encountered in processing.

Each file is assigned an integer identification number as it is encountered, and the file is stored in a directory and filename structure based on that integer.

The numbering starts at one (1). A directory is created for every 1,000,000 files, and in each of those directories, a directory is created for each 1,000 files. The filename is a nine character left-padded string (e.g. $filename = sprintf("%09d", $fileID) ).

Thus file number 1 is stored in the directory/filename "000/000/000000001". File number 12,345,678 is stored in "012/345/012345678".

A tab-delimited file is available which contains the corpus location, SHA-1, byte count and full original path of each file in the corpus. 650MB Zip file and for the file hash signature. Check here for an example view of this data.

Digital evidenceInformation technologySoftware research

## Contacts

                -      General Comments or Questions    nsrl@nist.gov   

-  **‹** Diskprints 
-  NSRL and Voting System Software **›** 

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