Managing Authenticity - PowerPoint Presentation

Slide1

Managing Authenticity

Silvio Salza,

silvio.salza@uniroma1.it

Maria

Guercio

,

maria.guercio@uniroma1.it

CINI -

Università

di

Roma “La

Sapienza

”Slide2

Authenticity

Authenticity is a

central concept

in Digital Preservation

A Digital Resource (DR) is authentic if it is actually what it pretends to be

and that it is free from tampering or corruption

Clearly authenticity depends on the competence and the reliability of the keeper of the resource

Ensuring authenticity implies the capacity of

controlling:

the identity of the DR

: that means the

reference

, the

context

and the

provenance

the integrity DR

: that means

that its original content has not been corrupted

. Slide3

Integrity

The

integrity

of a resource means that the preserved resource is

complete and uncorrupted in all its essential components

.

An evident property for

material objects

, since in this case

the original object is preserved

Digital resources are preserved as

copies of the original object

, and undergo

transformations

(e.g. format and/or physical support migrations) due to technological obsolescence

Checking the integrity

becomes a

far more complex process

:

even if

the original

bitstream

may be compromised

.....

the content

, i.e. the essential components,

may still be preservedSlide4

Identity

The

identity of a resource

primarily refers to its

unique designation and/or identification

, but is more than that

It refers to

the whole

of the characteristics

of a resource

that

uniquely identify it and distinguish it from any other resource

This

heavily depends on the environment

and includes:

The

internal conceptual structure

of the resource

The

general context

(administrative, legal, documentary, technological, some could even add social)

The

provenance

: where does it come from? How did it get to usSlide5

Why is authenticity crucial ?

The need to preserve

authentic information content

(not tampered and able to prove its persistency) cannot be questioned:

it is firmly based on common sense

To understand the

central role of authenticity

in the digital preservation process we must concentrate on two aspects:

the

dynamic nature of the preservation process

which endangers the integrity of the information content; and

the need

to be able to assess the identity, integrity and provenance

of resources, that have undergone during their lifecycle a series of transformationsSlide6

Authenticity in a digital environment

In a traditional environment an

uninterrupted chain of custody

is generally sufficient to guarantee the authenticity of the preserved

resorces

Digital Resources (DR) are instead

very vulnerable

and can be easily

forged or corrupted without leaving any evidence

Transmission

of digital object along the chain of custody is a very delicate process:

transmission channels are quite vulnerable

Authenticity of digital resources can be therefore affected by:

transformations

(due to technological obsolescence)

changes of custody

the DR undergoes during its lifecycle.

As a consequence, authenticity

cannot be recognized as given once and for ever

within a digital environmentSlide7

Authenticity in OAIS and InterPARES

OAIS

(2012 version):

“The degree to which a person (or system) may regard an object as what it is purported to be. The degree of authenticity

is judged on the basis of evidence

”

InterPARES

:

The

authenticity

has no degree in itself

The

presumption of the authenticity

is graduated

The assessment is supported by:

the preservation system

the evidence collected during the lifecycle

(both before and after preservation begins)Slide8

Authenticity in CASPAR

The

CASPAR

project (2006-2009) provided a crucial contribution to the problem of managing authenticity in Long Term Digital Presentation (LTDP) repositories:

has provided a

model based on OAIS and InterPARES principles

for managing authenticity in order to allow to assess it at a later time

has identified a

set of attributes

that allows to capture evidence along the DR lifecycle and to collect it

has developed

specific procedures

to

manage authenticity

: authenticity management protocolsSlide9

The APARSEN contribution

APARSEN

proposes a

methodology for the management of the authenticity of Digital Resources (DR)

:

Formal authenticity model

: to represent the DR lifecycle and the management of authenticity evidence

Operational guidelines

: to guide the process of instantiating the model in a specific environment

Case studies

: carried out to tune the methodology and test its effectiveness in a set of heterogeneous environmentsSlide10

Authenticity and the DR lifecycle

Transformations relevant to the DR authenticity may occur even

before preservation begins

The authenticity management process must encompass

the whole DR lifespan since its creation

Interoperability becomes a crucial requirement

to be supported by the authenticity management policy

Authenticity is affected by

transformations

and

changes of custody

the DR undergoes during its lifecycle. To assess authenticity one needs to

collect and preserve appropriate evidence

in order to be able, at a later time,

to trace back these transformations Slide11

Modeling the digital resource lifecycle

PRE-INGEST PHASE

: from the creation of the DR to the beginning of the Long Term Digital Preservation (LTDP) process

LTDP PHASE

: encompasses all the transformations and the changes of custody the DR goes though along the LTDP processSlide12

Collecting authenticity evidence

The first step is to

identify the relevant lifecycle events

These are typically of two kinds:

Changes of

custody

: the DR is moved to a different repository

Transformations

: the format, or more in general the way the DR is recorded and preserved, is changed

In both cases

authenticity evidence must be collected

, to allow assessing the authenticity at a later time.

For each event one must specify

:

Which

evidence

should be

collected

How should it be organizedSlide13

Authenticity Evidence Records (AER)

Authenticity Evidence Record (AER):

structure containing the evidence collected in connection with a specific event

Authenticity Evidence History (AEH):

incremental structure of AERs

At any moment, scanning the AEH allows to trace back all the transformation the DR has undergone, and therefore to establish the authenticity and the provenance of the DR Slide14

Authenticity Protocols

Authenticity

Evidence Record (AER):

defines which

Authenticity Evidence Items (AEIs)

must be collected (

data level

)

Authenticity Protocol (AP)

defines which sequence of actions should be performed in order to collect these items (

procedural level

)

Authenticity Protocol (AP):

the procedure to be followed,

in connection with a given lifecycle event

, to perform the controls and to collect the authenticity evidence which is preserved in the Authenticity Evidence RecordsSlide15

The need for interoperability

Typically, a DR undergoes several

changes of custody

along its lifecycle

Systems have

to deal with evidence collected by other systems

Proper definition and standardization of

AERs

are crucial steps towards interoperability

The hearth of the problem is:

Organize the authenticity evidence within the AERs in such a way that it can be reasonably interpreted by a system different from the one that collected itSlide16

Achieving interoperability

Interoperability

should be achieved through

standardization

: notably standardization of the AER structure and format

It is the final goal, but it may be a very long process and requires a large consensus

Providing

guidelines

that could be

reasonably

implemented

is an important preliminary step

The APARSEN has developed a set of

operational guidelines

The guidelines have been

successfully tested

to instantiate the APARSEN authenticity management model

in several different environments

(case studies)Slide17

The operational guidelines

STEP 1

.

Understanding the needs of the Designated Community

STEP 2

.

Identifying relevant lifecycle events

STEP 3

.

Defining the policy and the Authenticity Evidence Record

STEP 4

.

Formalizing Authenticity Protocols

Systematic procedure to be followed when instantiating the model in a specific environment to get to the definition of an appropriate authenticity management policySlide18

1 – Understanding the Designated Community

This is

a crucial preliminary step

The

Designated Community

is a central concept in the

OAIS reference model

It includes both the

Producers

and the

Consumers

, i.e. those

interested in maintaining long term access to the DRs

Authenticity may have quite a

different meaning to different communities

One needs to understand

which kind of evidence is important

for a given community, to

define the policy accordinglySlide19

2 – Identifying the lifecycle events

The approach is especially effective in environments with

systematic workflows

:

large

and

stable

flows

of DRs

each DR undergoes the

same

transformations

and

changes of custody

during its lifecycle

Only

events relevant to authenticity

, according to the needs of the designated community, must be considered

The lifecycle is clearly identified according to the APARSEN modelSlide20

3 – Defining the policy

First compare the

current practices

and

what should be done

according to the best practices

What if

some checks are not performed

, and

some evidence items are not collected

?

There may be good reasons to do that

For instance in some environments restricted access and enforced security policies

may guarantee for the integrity of DRs

Once the appropriate evidence and actions have been selected, the policy

should specify for each relevant lifecycle event

:

The

checks

that have to be performed

The evidence items to be collected and preserved in the AERSlide21

4 – Formalize the authenticity protocols

APARSEN

has extended and brought to concrete implementation a concept originally introduced by

CASPAR

, a seminal project in digital preservation

An

AP

has to be defined for each event in the lifecycle model

The

AP

is organized as a sequence of

Authenticity

steps (AS)

.

Each

AS

is a set of elementary actions meant to:

perform a specific

control

and/or collect one or more Authenticity Evidence Items (AEI)The execution of the AP for a given lifecycle event generates the Authenticity Evidence Record (AER) for that eventSlide22

Case study: Vicenza Health Care system

Regional

repository of the Italian Public Health Care

System

Complies with complex and demanding Italian regulations on LTDP

Authenticity

is a crucial requirement in the Health Care environment:

Scientific relevance of the data

Attribution of legal responsibilities

Manages

several kinds of digital resources: test results, diagnostic images, medical

reports.

Several systematic workflows, for instance the

Radiology Information System (RIS)

workflow:

Reports digitally signed (crucial authenticity and provenance evidence)

G

o through several transformations and changes of custody Slide23

The RIS lifecycle modelSlide24

Example: AER for INGEST

AEI-1. Event type

: INGEST

AEI-2. Original identifier

:

identifier from the report metadata.

AEI-3. Identifier in the LTDP system

:

ID-DOC generated by Scryba

AEI-4. Context information

:

DICOM identifier of the study to which the report refers.

AEI-5. Date and time of the ingestion

:

from the certified timestamp

AEI-6. Identification and authentication data of the LTDP system administrator

:

generated by Scryba

AEI-7. Assessment on the authenticity and provenance

:

outcome of controls on the digital signature

AEI-8. Digest of the AIP

: from the certified timestamp.Slide25

Example: AP for INGEST

25

Agent

:

Administrator of the LTDP repository

AER

: (as defined above)

Authenticity Step (AS) sequence

:

AS-1

: check provenance

AS-2

: check integrity

AS-3

: check context

AS-4

: generate internal identifier

AS-5

: generate timestamp

AS-6

: generate

AEI

:

Original identifier

AS-7

: generate

AEI

:

Internal identifier

AS-8

: generate

AEI

:

Context information

AS-9

: generate

AEI

:

Date and time

AS-10

: generate

AEI

:

Administrator data

AS-11

: generate

AEI

:

Assessment of authenticity and provenance

AS-12

:

generate

AEI:

Digest of the AIPSlide26

Example: Authenticity step

26

AS-1 for INGEST: check provenance

AS-1.1

: get the digital signature certificate from the pkcs#7 file

AS-1.2

: get the original digital certificate from the Certification Authority

AS-1.3

: check the certificate in the pkcs#7 file against the original certificate

AS-1.4

: check the expiration date in the digital certificate against the current date

AS-1.5

: get the revocation list from the Certification Authority and check it

AS-1.6

: if any of the checks in

AS-1.3

,

AS-1.4

and

AS-1.5

fails

then abort ingestion Slide27

Conclusions

Authenticity of Digital Resources

is affected by

relevant

lifecycle

events

:

transformations

and

changes of custody

Authenticity Evidence

should be systematically collected

along the whole DR lifecycle

APARSEN

proposes a

systematic methodology

:

Formal model

of the DR lifecycle: identify relevant eventsSpecifiy controls to be performed and evidence to be gatheredAuthenticity Evidence Records to ensure interoperabilityOperational guidelines to guide implementation of the modelThe methodology has been tested on several case studies, by successfully implementing it in a variety of environmentsSlide28

Guide to further reading - 1

APARSEN Project: Deliverable 24.1.

Report on Authenticity and Plan for Interoperable Authenticity Evaluation System

(2012).

http://www.alliancepermanentaccess.org/wp-content/uploads/downloads/2012/04/APARSEN-REP-D24_1-01-2_3.pdf

[visited 22 June 2014].

APARSEN Project: Deliverable 24.2

. Implementation and testing of an authenticity protocol on a specific domain.

(2012).

http://www.alliancepermanentaccess.org/wp-content/uploads/downloads/2012/04/APARSEN-REP-D24_2-01-2_2.pdf

[visited 22

une

2014].

Authenticity Task Force, Appendix 2

: Requirements for assessing and maintaining the authenticity of electronic records.

In: The long-term preservation of authentic electronic records: findings of the InterPARES Project, Luciana

Duranti

, (ed.), San

Miniato

, Italy,

Archilab, pp 204–219 (2005). http://www.interpares.org/book/interpares_book_k_app02.pdf [visited 22 June 2014].Briguglio L., Salza S., Guercio G.: Preserving Authenticity Evidence to Assess Provenance and Integrity of Digital Resourcesin. In Information Technologies for Performing Arts, Media Access, and Entertainment. In: Nesi P., Santucci R.: Information Technologies for Performing Arts, Media Access, and Entertainment. LECTURE NOTES IN COMPUTER SCIENCE, vol. 7990, p. 66-77, Berlin Heidelbereg:Springer-Verlag (2013)Slide29

Guide to further reading - 2

CASPAR conceptual model of authenticity

(CASPAR-D1201-TN-0101-1_0).

http://www.slidefinder.net/c/caspar_authenticity_position_paper/32860963

[visited 22 June 2014].

Giaretta

, D.:

Advanced digital preservation

(specifically

chapt

. 13 and sect. 17.11). Springer-

Verlag

, Berlin-Heidelberg (2011).

Guercio

M.:

La notion d'authenticité en conservation numérique

. In Musique et technologie. Préserver - Archiver -

Re-produire

: musique et technologie, jeux vidéo, Paris, Institut national de l’audiovisuel: 75-92 (2013)

Guercio M., Salza S.: Managing authenticity through the digital resources lifecycle. In: Agosti M. et al.(eds), Digital Libraries and Archives, 8th Italian Resarch Conference, IRCDL 2012, Bari, Italy, February 2012. Revised Selected Papers. Communications in computer and information science - CCIS", 354 , © Springer-Verlag Berlin Heidelberg: 249-260 (2013)Salza S., Guercio M.: Authenticity management in long term digital preservation on medical records. In: I-Pres. Proceedings of the 9th International Conference on preservation of digital objects. Toronto, October 1 – 5, 2012, University of Toronto: 171-179 (2013) http://ipres.ischool.utoronto.ca/sites/ipres.ischool.utoronto.ca/files/iPres%202012%20Conference%20Proceedings%20Final.pdf [visited 22 June 2014].Slide30

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