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A Method to Select Objects for Periodic Fixity Check in Digital Archive Systems

IP.com Disclosure Number: IPCOM000236888D
Publication Date: 2014-May-21
Document File: 5 page(s) / 57K

Publishing Venue

The IP.com Prior Art Database

Abstract

Digital archive systems are capable of storing, managing and locating/retrieving millions (and sometimes billions) of documents, which have accumulated over the course of an individual or organization's lifetime. The core artifact maintained in an archive system is the Archive Object (AO). Many archive systems need to perform periodic fixity checks of their stored AOs to ensure their integrity. The periodic fixity check is generally a low-priority background process that should not disturb the normal operation of the archive system, and thus is given limited resources. The problem we address is the selection of the AOs to check on each cycle of the periodic fixity check. Performing fixity checks on all AOs may not be applicable, because most archives contain too many of them, and we have limited resources dedicated for this background process.

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Page 01 of 5

A Method to Select Objects for Periodic Fixity Check in Digital Archive Systems


1. Background: What is the problem solved by your invention?
Describe known solutions to this problem (if any). What are the
drawbacks of such known solutions, or why is an additional
solution required? Cite any relevant technical documents or
references.

Digital archive systems are capable of storing, managing and
locating/retrieving millions (and sometimes billions) of
documents, which have accumulated over the course of an
individual or organization's lifetime. The digital archive market
is estimated to grow to 27,200 PB in 2010. In general, digital
archives consist of documents which have been selected for
permanent or long-term digital preservation, due to their
enduring value or regulatory requirements.

The core artifact maintained in an archive system is the Archive
Object (AO). An AO consists of the raw Content Data Object (CDO)
to be archived, along with metadata focused on describing the
past and present states of that CDO. These may include metadata
to ensure the CDO is uniquely identifiable, to describe its
provenance and context, and prove it has not been altered in an
undocumented manner. Much of the metadata reside in storage
suitable for fast access such as a database or extended
attributes of a file system.

One of the important metadata attribute of the AO is its fixity
value, which includes an integrity check value to prove that the
particular content information has not been altered in an
undocumented manner. Many archive systems need to perform
periodic fixity checks of their stored AOs to ensure their
integrity. More specifically, the Open Archival Information
System (OAIS), an ISO standard since 2003 (ISO 14721:2003 OAIS)
[1], states that the archival storage should perform such
periodic fixity checks. The periodic fixity check is generally a
low-priority background process that should not disturb the
normal operation of the archive system, and thus is given limited
resources.

The problem we address is the selection of the AOs to check on
each cycle of the periodic fixity check. Performing fixity checks
on all AOs may not be applicable, because most archives contain
too many of them, and we have limited resources dedicated for
this background process.

    We searched for the following keywords: periodic fixity
check, fixity check selection, fixity check rank, fixity check
priority, integrity check. We didn't find previous art that
strives to address this problem. Related work discusses fixity
but it's not about selecting objects for fixity checks. There are
many patents and methods for integrity of files. For example, the
following patent suggests a fixity computation method, but it
doesn't discuss what object to select for fixity check:


Page 02 of 5

ยท Patent [2] describes a method and system for conducting an
integrity check of system and user metadata when the
metadata is mounted. A filesystem reviewer is embedded
within software of a server node. A mutual exclusion lock i...