Dr. Hrvoje Stančić, full professorDirector Team Europe, InterPARES Trust

Department of Information and Communication SciencesFaculty of Humanities and Social Sciences

University of Zagreb, Croatia

hrvoje.stancic@zg.t-com.hr

San Jose, Costa Rica, 19 February 2020

Contents

1. Introduction2. e-Signatures3. ETSI EN 319 102-14. InterPARES Trust Study – TRUSTER5. Blockchain enabling concepts6. TrustChain model7. Conclusion

InterPARES Trust - Trust in Digital Records in an Increasingly Networked Society, San Jose, Costa Rica, 19 February 2020 2

1. Introduction

• Documents and records today – increasingly – created, analysed, used, reused

in the digital form

• Long-term preservation (LTP) of digital records– e.g. 11 years, 70 years, permanently

• TRUSTER research – focus on a particular challenge– LTP of digitally signed or sealed records

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1. Introduction …

• LTP challenges – how to preserve

4

• authenticity• integrity• reliability• usability

• non-repudiation• security• confidentiality

InterPARES Trust - Trust in Digital Records in an Increasingly Networked Society, San Jose, Costa Rica, 19 February 2020

2. e-Signatures

• Advanced e-signature (a) it is uniquely linked to the signatory(b) it is capable of identifying the signatory(c) it is created using means that the signatory can maintain under his sole control, and(d) it is linked to the data to which it relates in such a manner that any subsequent change of the data is detectable

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• Advanced e-signatures rely on qualified certificates• guarantee the authenticity

and the identity of the signatory

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2. e-Signatures ...

• Challenges with e-signatures– short expiration period– possibilities of certificate revocation– the need for resigning– dependence on the certification authorities

("trusted third parties")

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2. e-Signatures ...

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2. e-Signatures ...

3. ETSI EN 319 102-1

Procedures for Creation and Validation of AdES Digital Signatures (Part one: Creation and Validation)

InterPARES Trust - Trust in Digital Records in an Increasingly Networked Society, San Jose, Costa Rica, 19 February 2020 9

Signer'sdocument

Signedattributes

Time stamp

Certificate andrevocation data

Archival time

stamp(s)

e-signature

Basic Signature (B-B)Signature with Time

(B-T)

Signature with Long Term Validation Material (B-LT)

Signature providing Long Term Availability and Integrity of Validation Material (B-LTA)

4. InterPARES Trust Study – TRUSTER

Model for Preservation of Trustworthiness of the Digitally Signed, Timestamped and/or Sealed Digital Records (TRUSTER Preservation Model)• Team: Hrvoje Stančić (lead), Victoria Lemieux, Natasha

Khramtsovsky, Enigio Time AB, Croatian Financial AgencyFINA, FHSS GRAs

• a model for blockchain-based Validity Information Preservation (VIP) solution

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5. Blockchain enabling concepts

1.Hash algorithm2.Merkle tree3.Chaining of top hashes4.Distributed consensus

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1. Hash algorithm

SHA-256 – example of a hash value of a document

7d8c5b62dcb440233f7eaac1ec49e4c386b8089c37d69ab51bc674b8877cb032

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2. Merkle tree

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[…] […]

H(D1) H(D10) H(D11) H(D20)

H(D1-D10) H(D11-D20)

H(D1-D20) – root/top hashH – hashD – document

2. Merkle tree

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Hash of the File1.docxHash of the File2.docxHash of the File3.txt

Calculated root/top hash

3. Chaining of top hashes

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[…] […] […] […] […] […]

4. Distributed (peer-to-peer) consensus

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Blocks' creation direction

Block documents

Block documents

Top hash

[…] […] […] […]

Hash of the previous

block

Block hash

Top hashHash of the previous

block

Block hash

Block n Block n+1

Distributedledger

Distributedledger

Blockchain

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6. TrustChain model

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TrustChain Node 4

TrustChain Node 4

TrustChain participating institution 4

TrustChain participating institution 3

TrustChain participating institution 2

TrustChain participating institution 1

TrustChain Node 1

TrustChain Node 1

TrustChain Node 3

TrustChain Node 3 TrustChain

Node 2

TrustChain Node 2

1. A request to register new document is

started

Private persons or institutions

TrustChain

TrustChainblockchain

Block 0

Block 1

Block 2

Block 3

New block

2. TrustChain instituions check the

signature and vote on its validity

3. Documents are registered in the

TrustChain blockchain

New documentsSignature validity

information

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20InterPARES Trust - Trust in Digital Records in an Increasingly Networked Society, San Jose, Costa Rica, 19 February 2020

Can you start before we develop TrustChain?

Register integrity of the records in the blockchain

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DMS / RMS / OAIS Archive

Document / record creators

Document / record users

Blockchain

document / record hash

timeClock

Shared ledger (TrustChain©)

receipt (chain of proof)

sealed block

timestamped block

verification

1. Confirm integrity2. Existence or creation at a point in time3. Confirm sequence4. Support/enhance non-repudiation5. Improve validation6. Preserve validity of e-signed records

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7. Conclusion

• By using Blockchain / TrustChain– establish the new generation of archival

and business-oriented e-services– enable anyone to connect using API– preserve authentic digital records

with the help of blockchainprinciples

– prove integrity– prevent fraud– gain transparency

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Resources• Bralić, V., Kuleš, M., & Stančić, H. (2017). A model for long-

term preservation of digital signature validity: TrustChain. In: I. Atanassova, W. Zaghouani, B. Kragić, K. Aas, H. Stančić, & S. Seljan (Eds.), INFuture2017: Integrating ICT in Society, pp. 89-113,https://www.researchgate.net/publication/321171227_A_Model_for_Long-

term_Preservation_of_Digital_Signature_Validity_TrustChain

• InterPARES Trust research disseminationhttps://interparestrust.org/trust/research_dissemination

– look for TRUSTER Preservation Model (EU31) documents

• Bralić, V., Stančić, H., Stengard, M., A Blockchain Approach to Digital Archiving: Digital Signature Certification ChainPreservation, Records Management Journal (to be published in 2020.) InterPARES Trust - Trust in Digital Records in an Increasingly Networked Society, San Jose, Costa Rica, 19 February 2020 24

Blockchain for authentic records – possible solutions –

Dr. Hrvoje Stančić, full professorDirector Team Europe, InterPARES Trust

Department of Information and Communication Sciences

Faculty of Humanities and Social SciencesUniversity of Zagreb, Croatia

hrvoje.stancic@zg.t-com.hrSan Jose, Costa Rica, 19 February 2020

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