1. New Technologies applicable to Document Management: Blockchain
Hrvoje Stancic, Ph.D., assoc. prof. Faculty of Humanities and Social Sciences University of Zagreb, Croatia

2. Contents Introduction eIDAS Regulation Hash function
Hash (Merkle) tree
Distributed network
Blockchain
Conclusion

3. 1. Introduction Electronic Document Management – motivation
business productivity
organizational effectiveness
The need for
version tracking
tracing steps (where/when the document was/is) in the business process
verification of changes, document structure, contents
trusted exchange of document (trusted third party)

4. 1. Introduction … Electronic Document Management Challenges
stand alone solutions
cloud solutions
Challenges
dealing with digital signatures, seals, time stamps
preservation of documents'
authenticity
integrity
reliability
usability
non-repudiation
security
confidentiality

5. 2. eIDAS Regulation
Regulation (EU) No 910/2014 of the European Parliament and of the Council of 23 July 2014 on electronic identification and trust services for electronic transactions in the internal market and repealing Directive 1999/93/EC
defines
advanced electronic signatures
qualified certificates
electronic seals
qualified electronic time stamps

6. 2. eIDAS Regulation ...
Advanced electronic signature – an electronic signature that
(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
Firstly defined in:
Directive 1999/93/EC of the European Parliament and of the Council of 13 December 1999 on a Community framework for electronic signatures

7. 2. eIDAS Regulation ...
Advanced e-signatures rely on qualified certificates
guarantee the authenticity and the identity of the signatory
are issued for the period of 2 to 5 years
expire
can be revoked (CRL – Certification Revocation List)

8. 2. eIDAS Regulation ... Advanced electronic seals
similar requirements as for the advanced e-signature with the difference that it relates to the creator instead of the signatory
also relay on the qualified certificates

9. 2. eIDAS Regulation ... Qualified electronic time stamps
(a) binds the date and time to data in such a manner as to reasonably preclude the possibility of the data being changed undetectably
(b) is based on an accurate time source linked to Coordinated Universal Time, and
(c) is signed using an advanced electronic signature or sealed with an advanced electronic seal of the qualified trust service provider, or by some equivalent method
Qualified trust service providers provide qualified validation service (granted the qualified status by the supervisory body).

10. 2. eIDAS Regulation ... Qualified electronic time stamps
use advanced electronic signatures and electronic seals
Advanced electronic signatures and electronic seals
rely on qualified certificates
authenticity
identity of the signatory

11. 2. eIDAS – example of electronic signature
Advanced electronic signature

12. 2. eIDAS – example of electronic signature

13. 2. eIDAS Regulation ... Challenges short expiration period
possibilities of certificate revocation
the need for resigning
dependence on the certification authority(-ies), i.e. qualified trust service providers ("trusted third party")

14. Archival time stamp(s)
2. eIDAS Regulation ...
Relies on ETSI standards
ETSI EN Electronic Signatures and Infrastructures (ESI); Procedures for Creation and Validation of AdES Digital Signatures
Archival Timestamps
Signature providing Long Term Availability and Integrity of Validation Material (B-LTA)
Signature with Time (B-T)
Signature with Long Term Validation Material (B-LT)
Basic Signature (B-B)
e-signature
Time stamp
Certificate and
revocation data
Archival time stamp(s)
Signer's
document
Signed
attributes

15. 2. eIDAS – example of electronic signature

16. 3. Hash function Hash or message digest
one-way function that calculates the unique fix-length string out of any document of any size
it is not possible to recreate the original document by knowing its hash
(theoretically) extremely difficult and nearly impossible to create "collisions" i.e. meaningful records with the same hash value (produced by a given hash function)

17. 3. Hash function …
Different hash functions (e.g. Adler32, Haval, MD, RipeMD160, SHA, Tiger, Whirlpool etc.) result with hash values of different lengths
Secure Hash Algorithm (SHA): e.g. SHA-256, SHA-512
Example:
hash of a document (.docx)
MD5: 614e8bb4b90a998a5faea456f
SHA-256: 7d8c5b62dcb440233f7eaac1ec49e4c386b8089c37d69 ab51bc674b8877cb032

18. 3. Hash function – example
Online MD5,
Received file
Calculated hash
Received
hash

19. 3. Hash function …
Hash in combination with electronic signatures can be used to check
record's integrity
authenticity of electronic signature

20. 3. Hash function … 1. Hash function Application of private key Hash
e-sign.
7d8c5b...
e-sign.
7d8c5b...
Hash
function 2.
Hash =
integrity check
Application of public key
e-sign.
Hash
7d8c5b...
electronic signature authenticity check

21. 4. Hash (Merkle) tree
Several (or many) hash values may be hashed together thus forming a Merkle or hash tree
Merkle, R. C. (1982). Patent No. US USA
H(D1-D20) – "root/top hash"
H – hash
D – document
H(D1-D10)
H(D11-D20)
[…]
[…]
H(D1)
H(D10)
H(D11)
H(D20)

22. 4. Hash (Merkle) tree – example
Online MD5,
Hash of the File1.docx
Hash of the File2.docx
Hash of the File3.txt
Calculated root/top hash

23. ≠ 4. Hash (Merkle) tree … Merkle (hash) tree
used by Satoshi Nakamoto for creating virtual/crypto currency Bitcoin
resulted with the evolvement of the blockchain technology
blockchain is the underlying technology enabling Bitcoin and many other applications
blockchain relies upon a distributed network and decentralized consensus ≠

24. 5. Distributed network Distributed (peer-to-peer) network
vs. centralised network – one central server
vs. decentralised network – several centres
all nodes (servers) are equal – no centre(s)
no single point of control or attack
Image source:

25. 5. Distributed network …
Enables the concept of decentralized consensus
every participant (node/server) records every event in its ledger ("main book"/database)
consensus is used in order to
ensure that all ledgers are the exact copies (i.e. are synchronised)
to determine truth
event (e.g. transaction or document) is valid only if qualified majority (50%+1 node) agrees upon it

26. 6. Blockchain A linked scheme based on hash (Merkle) tree
Hashes of individual events or files are created and timestamped
The group of hashes are hashed (a block is created), timestamped and made public (over the distributed network) in regular intervals (e.g. every second, every minute, every 10 or 15 minutes etc.)
Hash of the previous block is included in the next block (thus creating a chain of blocks)

27. 6. Blockchain …
Blockchain formation
[…]
[…]
[…]
[…]
[…]
[…]

28. 6. Blockchain … […] […] […] […] Blocks' creation direction Block n
Hash of the previous block
Top hash
Block hash
Hash of the previous block
Top hash
Block hash
[…]
[…]
[…]
[…]
Block documents
Block documents

29. 6. Blockchain – example
An example from the Enigio Time's time:beat solution (

30. 6. Blockchain – example …
Confirm that a particular document existed at a particular time (proof of contents, copyright etc.)
+ a secure time stamp is created

31. 6. Blockchain – example …

32. 6. Blockchain – example …
President of the Association of Catalan Archivists and Vice-president of the Croatian Archival Society get blockchained (this morning)

33. 6. Blockchain … The chain is formed of the linked blocks
Each additional block reinforces the preceding ones
Any attempt to modify a block will invalidate subsequent blocks and will be detected
Even authorized changes are virtually impossible
[…] X X X X X X X X

34. 6. Blockchain … Document verification
the distributed ledger can be updated with a document only if qualified majority of participating nodes agree it can be verified as a document 
the chain contains proof that a document was part of original set of documents the chain was built upon
[…]

35. 6. Blockchain … Public blockchain Private blockchain
Anyone can freely write data without permission granted by any authority
Only known and trusted (authorized by an authority) participants can freely write data
No point of control
(except initial authorization)
(Relative) anonymity
No anonymity
Examples: Bitcoin, Ethereum
Example: a group of partnering archives

36. 6. Blockchain – implementation possibility
Connecting a document management system with the blockchain via a blockchain aggregator
Shared ledger (TrustChain©)
timestamped
block
verification
time
Blockchain aggregator
sealed block
Publication channels
Clock
document hash
receipt (chain of proof)
Document creators
DMS
Document users

37. 6. Blockchain – research
On-going research as part of the InterPARES Trust ( project: Model for Preservation of Trustworthiness of the Digitally Signed, Timestamped and/or Sealed Digital Records (TRUSTER Preservation Model)
investigating the possibilities of using linking based timestamping and blockchain technology for long-term preservation of digitally signed records
developing a TrustChain© model

38. 7. Conclusion Blockchain can be used in document management to
confirm integrity of a document
confirm that a document was existing or created at a certain point in time (i.e. not after it was timestamped and registered in the blockchain)
confirm sequence of documents thus strengthening document versioning
support/enhance non-repudiation of a document
improve the validation possibilities of digitally signed documents/records during the long-term preservation

39. 7. Conclusion …
ISO/TC 307 – Blockchain and electronic distributed ledger technologies
new standard being developed
Document management, recordkeeping and archiving in the digital age
archivists need to understand new technologies in order to be able to evaluate their impact, and include them in archival processes
Act proactively and be able to offer professional opinions!
Embracing new technologies will result in very personal gains for archivists.

40. INFuture2017:  Integrating ICT in Society Zagreb, 8-10 November 2017 The Westin Zagreb Hotel

41. Sources
A gentle introduction to blockchain technology. (2015). [8/8/2016] A gentle introduction to digital tokens. (2015). [8/8/2016] A gentle introduction to smart contracts. (2016). [8/8/2016] Almgren, H. and Stengård, M. (2016). How to maintain Authenticity and Integrity of Electronic Information without Utilizing Electronic Certificates. In: Anderson, K. et al. e-Institutions - Openness, Accessibility, and Preservation (pp ). Department of Information and Communication Sciences, Faculty of Humanities and Social Sciences, University of Zagreb, Croatia, Bisht, K. (2016). The Blockchain and Decentralized Consensus. [8/8/2016] Directive 1999/93/EC of the European Parliament and of the Council of 13 December 1999 on a Community framework for electronic signatures. [8/8/2016] Duranti, L., & Blanchette, J.-F. (2004). The Authenticity of Electronic Records: The InterPARES Approach. Archiving Conference, Archiving 2004 Final Program and Proceedings (pp ). Society for Imaging Science and Technology. Guess, M. (2016). IBM wants to move blockchain tech beyond Bitcoin and money transfer. [8/8/2016] Hallam, S. (2016). The Blockchain vs Bitcoin. [8/8/2016] IBM Blockchain. [8/8/2016] In a nutshell: MultiChain. (2016). [8/8/2016] Merkle, R. C. (1982). Patent No. US USA. Nakamoto, S. (2008). Bitcoin: A Peer-to-Peer Electronic Cash System. Stančić, Hrvoje. Long-term Preservation of Digital Signatures // Technical and field related problems of traditional and electronic archiving / Gostenčnik, Nina (ur.). Maribor : Pokrajinski arhiv, , Brzica, Hrvoje; Herceg, Boris; Stančić, Hrvoje. Long-term Preservation of Validity of Electronically Signed Records // Information Governance / Gilliland, Anne ; McKemmish, Sue ; Stančić, Hrvoje ; Seljan, Sanja ; Lasić-Lazić, Jadranka (ur.). Zagreb : Department of Information and Communication Sciences, Faculty of Humanities and Social Sciences, University of Zagreb, , time:beat by Enigio. [8/8/2016] What is the Hyperledger Project?. [8/8/2016] Yaqub, J. (2015). Blockchain As A Database. [8/8/2016]

42. New Technologies applicable to Document Management: Blockchain
THANK YOU!
New Technologies applicable to Document Management: Blockchain
Hrvoje Stancic, Ph.D., assoc. prof. Faculty of Humanities and Social Sciences University of Zagreb, Croatia