Blockchain Certiﬁcation and Granular Editing Permissions in Document

Management System

Filippo Eros Pani

, Giacomo Ibba

, Michele Marchesi

, Andrea Pinna

, Simone Porru

Roberto Tonelli

and Bartolomeo Valcalda

T Bridge S.p.A., Genova, Italy

Department of Mathematics and Computer Science, University of Cagliari, Italy

Department of Electrical and Electronic Engineering (DIEE), University of Cagliari, Italy

roberto.tonelli@dsf.unica.it

Keywords:

Document Management, Blockchain, Decentralized Applications, Smart Contract, Collaborative Editing.

Abstract:

Ever-growing digitalization and increasingly competitive markets are driving industry and the public sec-

tor into fast-paced transformation. Competitive advantage is being acquired through technology investments

made possible by previously unavailable resources, freed by process automation, simpliﬁcation, and rational-

ization. Under these contingencies, we propose an innovative document management platform, featuring a

collaborative document editing technique and a blockchain certiﬁcation procedure. The two proposing parties

- a private company and an academic organization - mutually agreed on employing open-source technologies

as a strategic means to promote software reuse and developer communities’ support, and consequently reduce

implementation costs and ensure interoperability.

1 INTRODUCTION

Ever-growing digitalization and increasingly compet-

itive markets require companies to adapt at a fast pace.

Technology investments ensure a competitive edge,

and such investments are made possible thanks to the

automation, simpliﬁcation, and rationalization of pro-

cesses which, in turn, unleashes previously unavail-

able resources. The potential market segment ad-

dressed by document management software offers a

plethora of products and services that support com-

munication and interoperability among different sub-

jects. These products and services usually target busi-

ness users, such as institutions and public administra-

tion. Document management solutions can especially

beneﬁt local public authorities. Public organizations,

usually relatively complex, can leverage such solu-

tions to save on storage space, application servers,

back-ofﬁce maintenance, and front-ofﬁce extensions

(Pani et al., 2015) On the other hand, managers are

increasingly interested in analysing how information

is managed within companies, since the associated is-

sues are often at the root of inefﬁciencies. In fact,

information management issues’ resolution sets the

base for a successful strategy. Documents-related

processes (Mahajan and Banerjee, 2018), in particu-

lar, need to undergo signiﬁcant transformations in or-

der to increase business productivity and process efﬁ-

ciency and, at the same time, reduce operating costs.

The solution proposed in this paper aims to be a cost-

effective solution for business users, in particular by

exposing features dedicated to information ﬂows and

communications support. In the context of a R&D

project, our aim is to offer an innovative software

platform, to be provided as “software-as-a-service”

(SaaS). The creation of electronic documents, com-

munication management, digital signing and stamp-

ing, document recording protocol, and secure trans-

mission, are all features that will be provided by the

document management platform. Multi-channel com-

munication will be ensured by leveraging mail, e-

mail (also certiﬁed email), fax, voice, and text mes-

sages. Storage and archiving processes will fulﬁll lo-

cal regulations (McHenry and Burt, 2018). We pro-

pose an innovative document management platform

featuring a collaborative document editing technique,

The platform is conceived to be remotely available as

a Rich Internet Application (RIA) (Fraternali et al.,

2010). The platform features include an innovative

blockchain based certiﬁcation procedure. We decided

to use the Aergo blockchain which was released in

2019 to be ”the blockchain for business” and allows

Pani, F., Ibba, G., Marchesi, M., Pinna, A., Porru, S., Tonelli, R. and Valcalda, B.

Blockchain Certiﬁcation and Granular Editing Permissions in Document Management System.

DOI: 10.5220/0008349902990306

In Proceedings of the 11th International Joint Conference on Knowledge Discovery, Knowledge Engineering and Knowledge Management (IC3K 2019), pages 299-306

ISBN: 978-989-758-382-7

299

the development of smart contracts.

In the second section of this paper, we present a

background of related works and our development ap-

proach. The third section describes the proposed sys-

tem. In particular, it ﬁrst presents the key elements of

our solution (the collaborative editing system and the

blockchain document certiﬁcation) and then discuss

the main features of this two elements focusing on re-

search questions and technological opportunity. Last

section presents the conclusions about the proposed

project.

2 BACKGROUND

A collaborative editing system is essentially system in

which users can contribute concurrently to the same

document in remote. The design of collaborative

editing platforms must take into account and address

the issues and risks related to this speciﬁc typology

of system. The research is very much in line with

the development of new technologies, such as the

blockchain. The new proposals of collaborative edit-

ing systems can refer on studies and results that have

been proposed for some decades. The collaborative

writing and related open questions were the subject of

a review of the 2004 (No

el and Robert, 2004). In this

work the collaborative writing activity was framed in

the Computer Supported Cooperative Work (CSCW)

research ﬁeld (Bannon and Schmidt, 1989).

The development of the system we proposed in

this paper can be framed in the current research on

decentralized collaborative editing platforms. This re-

search focuses on the development of web based ap-

plications in which RIAs are included. In particular,

technologies like cloud computing and decentralized

system allowed the design of new architecture of edit-

ing platform, studied to work also in mobility (Ahmad

and Imine, 2015) (Resmi and Taiani, 2017). New sys-

tems take into account the need for more efﬁcient edit-

ing algorithms, such as the Commutative Replicated

Data Type (Lv et al., 2018).

The blockchain technology for the decentralized

document management is currently the object of in-

vestigation. This technology is suitable for provid-

ing a veriﬁable and unchangeable time marking to a

document. First studies proposed to implement time

stamping by using the Bitcoin protocol (Gipp et al.,

2015) (Gao and Nobuhara, 2017). Differently, in our

approach we want to exploit the newest generation

of blockchain system, which provides a smart con-

tract environment. The smart contract allows to im-

plement several features, such as the control of ac-

cessing. In the past, we saw the Ethereum network

as the absolute protagonist in this application ﬁeld

(Nizamuddin et al., 2019). Ethereum was the ﬁrst

blockchain studied to develop decentralized applica-

tions. Instead of Ethereum we proposed the use of

the Aergo blockchain network, developed in 2019 and

studied explicitly for business applications.

2.1 Development Approach

For the software development activities related to

the project, the lean-based software development ap-

proach proposed in (Lefﬁngwell, 2010) is being em-

ployed. Such approach was selected not only for the

initial implementation, but also for the maintenance

and evolution phase. More speciﬁcally, Kanban, a

tool used in lean methodologies, has been used in

maintenance processes (Anderson, 2012). This ﬂexi-

ble approach has several advantages when compared

to older approaches, especially considering its capa-

bility to meet the actual needs of the IT industry.

Being it considerably different from more common

methodologies used within the IT industry, its impact

at the marketing, organizational, and company level

is still to be fully understood. Nevertheless, leverag-

ing the afore-mentioned approach helps a single de-

veloper team in dealing with the management of con-

current projects - a scenario that is neither ideal nor

uncommon.

3 THE SOLUTION PROPOSED

The proposed document management platform is be-

ing devised to be a set of safe and reliable web-based

RIA tools for both individuals and companies, with

the aim of allowing communication with public in-

stitutions, banks, private companies, freelancers, and

other entities. The solution features two main innova-

tive aspects:

• a dedicated collaborative document editing tech-

nique;

• a document certiﬁcation procedure based upon the

blockchain technology.

In ﬁg. 1 the main elements of the proposed solu-

tion are represented. The key aspects of the research

relating to the elements of the proposed system will

be described below.

3.1 Collaborative Document Editing

Research has been conducted on the collaborative cre-

ation of complex documents such as:

• invitations to tender;

KMIS 2019 - 11th International Conference on Knowledge Management and Information Systems

300

Figure 1: Conceptual diagram of the main elements of the proposed document management platform.

• technical projects;

• contracts;

• commercial offers;

• administrative acts.

The platform allows to support users’ real-time inter-

actions during document drafting. In particular, the

platform structuring the document into separate sec-

tions with a speciﬁc type of access and editing. Users’

collaboration and interaction is also eased by dedi-

cated auxiliary features, such as the ability to high-

light the text of each author with a different colour, or

the real-time chat window. The general objectives are

as follows:

• simplify and make the preparation of a complex

document more efﬁcient, even in case of multi-

organization editing;

• ease management and control of the drafting of a

document while maintaining granular responsibil-

ity levels;

• create links and interactions between the docu-

ment and the organization’s processes;

• simplify and make document signing processes

more user-friendly;

• uncouple, as far as possible, the semantic value

of the information from its representation, and the

medium where it is presented.

As regard the non-functional requirements of the

document platform, each application component, in

addition to ensuring an optimal user experience, must

be available to organizations both on-premise and in

the cloud; among other advantages, this would allow

to maintain direct control of the data that are most

critical. The platform design requires the implemen-

tation of the ECM Enterprise through the CMIS stan-

dard (OASIS Standard, 2015). This will make it pos-

sible to replace the ECM component at any time with-

out any modiﬁcation to the general architecture. The

interfaces of the various application components en-

sure a modern user experience in order to facilitate

users in completing their tasks. On the other hand, as

for the functional requirements, an innovative feature

is the possibility to structure a document into separate

sections with speciﬁc user access and editing permis-

sions, as mentioned before. A user with speciﬁc per-

missions must be able to create a new document by

deﬁning its descriptive metadata. Then, the system

automatically assign the role of document responsi-

ble. The user responsible for the document must be

able to deﬁne the structure of the document by creat-

ing appropriate independent sections. When ﬁrst con-

ﬁguring a section, it is possible to associate to the sec-

tion the responsible person, by selecting them from

the users’ system database. The section responsible

can also deﬁne the team of users that are involved in

the creation of that speciﬁc section. When multiple

users access the section’s editing tools, their presence

and actions are visible to all the other authors, ensur-

ing real-time collaboration editing. The editorial pro-

cess of a section comprises the following steps:

• opening of the editing phase;

• collaborative editing by users with permission on

the speciﬁc section;

• request for approval of the product content at any

time;

• approval of the changes by the section manager.

Regarding the versioning, each single version created

must be stored in the system’s database and made

accessible to the users. Metadata such as creation

time and date, contributors, as well as the content of

each single version, must be recorded. Each version

must be automatically and sequentially numbered,

and must indicate if it was approved by the section’s

responsible during the approval process. Moreover,

the platform must provide the section’s editors a ded-

icated communication environment for that speciﬁc

section. This communication channel must allow to

view all messages sent by the users, and possibly fore-

see the exchange of private messages. The same com-

munication channel must be used by the system to

Blockchain Certiﬁcation and Granular Editing Permissions in Document Management System

301

provide automatic notiﬁcations about the main events

related to the section itself.

3.2 Blockchain Document Certiﬁcation

Another research activity concerned making the doc-

ument’s main responsible capable of ensuring docu-

ment immutability through blockchain document cer-

tiﬁcation. To this purpose, the system allows to

publish the document on a blockchain by simply

initiating the blockchain publication process on the

page dedicated to the relevant document’s version.

Once the document is successfully published on the

blockchain, and the mining activities are completed,

the system will allow to visualize the publication

time and date, the transaction ID, and the number of

blockchain conﬁrmations.

3.2.1 Blockchain for Document Management:

An Overview

The use of blockchain technology in document man-

agement presents various advantages coming from

the intrinsic properties of the technology itself, like

documents unalterably, simpliﬁcation of internal pro-

cesses, managing information conﬁdentiality, cryp-

tography and private key management for accessing

the system. A blockchain is a growing list of records,

called blocks, which are sequentially linked using

cryptography. Each block contains a cryptographic

hash of the previous block, a timestamp, and transac-

tion data. By design, a blockchain is proof tamper to

data modiﬁcation, indeed is deﬁned as ”an open, dis-

tributed ledger that can record transactions between

two parties efﬁciently and in a veriﬁable and perma-

nent way”(Nakamoto et al., 2008).

Currently, several business enterprises propose

blockchain based solutions in ﬁeld of document man-

agement. Among these we mention Blocko (https:

//www.blocko.io/platform.html), Storj Labs (https://

storj.io/) and Cryptyk (https://www.cryptyk.io/), three

companies which are trying with their blockchain and

smart contract based solutions to revolutionize the ref-

erence market by proposing more efﬁcient and sus-

tainable solutions(Salmer

on-Manzano and Manzano-

Agugliaro, 2019). Fields of application includes:

• Distributed Document Management: A docu-

ment is stored on multiple machines perfectly syn-

chronized to work at a speciﬁc document at the

same time.

• Security: A document can be encrypted so that

the owner of the encryption itself, is the only one

to be able to access to that document.

• Multisignature: A document can be owned by a

set of predeﬁned owners who can act upon only

if all the owners or a predeﬁned fraction of them

agree.

• Traceability: Could be useful on food industry to

keeping track of the origin and the freshness of a

product and keeping information about transport.

• Certiﬁcation: Blockchain could be useful to

demonstrate authenticity and ownership of a doc-

ument.

• Recognition: Blockchain is becoming popular on

the management of documents which allow iden-

tiﬁcation such as identity cards and passports, so,

because of this, the blockchain could be used to

simplify task as boarding and landing of passen-

gers.

• Timestamping: Associating a timestamp to a

document establishes a legally valid date and time

to that document.

The role of the blockchain technology and especially

that of smart contracts is continuously emerging to

support new features of software systems. Many stan-

dard features of software systems can be implemented

within the blockchain which plays the role of decen-

tralized services (also called blockchain as a service

- BaaS)(Daniel and Guida, 2019) or microservices

(Tonelli et al., 2019).

3.3 Document management with Aergo

Aergo (AERGO, 2019) is a blockchain project for

business applications recently launched by the com-

pany Blocko. The ﬁrst version of the platform was

released on 9 April 2019. Aergo (AERGO, 2019) is

a hybrid blockchain which tries to gather the advan-

tages of private and public blockchains. It is Proof of

Stake (Bitcoinwiki, 2019) based, so every user must

prove that he owns a certain amount of tokens.

Another interesting feature of Aergo is that it uses a

particular protocol of interoperability called Merkle

Bridge to allow more chains to communicate with

each other. Furthermore it implements the possibility

of Merkle proofs usage to create a communication be-

tween Ethereum and Aergo to demonstrate and certiﬁ-

cate the existence of something in another blockchain.

Merkle bridge could be seen as a multi-signature con-

tract which signs the state of the root of a sidechain in-

stead of signing individual transactions, like in other

blockchain implementations. Aergo allows to inter-

act with the blockchain with different programming

languages, in particular Java, Javascript and Python.

For Java there is Heraj, for Javascript Herajs, and the

KMIS 2019 - 11th International Conference on Knowledge Management and Information Systems

302

Python library is called Herapy (AERGO contribu-

tors, 2019) .

We ﬁrst analyze Heraj which provides fea-

tures and functionality to interact with the Aergo

blockchain and with the development and the execu-

tion of smart contracts. Next we will have a look at

how Heraj could be used to deploy a Lua smart con-

tract.

Aergo Smart Contracts. Aergo allows to develop

and run smart contracts using LUA language and

Athena-Ide, which is an extension of the Atom

text editor. In addition Aergo provides a testnet

blockchain in which it is possible to run and test de-

centralized applications without spending real Aergo.

By following the instructions given by the company

available at (AERGO team, 2019) everyone can ob-

tain an Aergo wallet and an Aergo account. Aergo

provides Aergo Connect, which is a blockchain bridge

that allows to connect to the Aergo blockchain with-

out installing a blockchain node. It is very similar to

the more famous Ethereum’s metamask. Thanks to

Aergo Connect it is possible to chose to work in the

Aergo main net or in the testnet. We worked using

the Aergo test net because it is free. Aergo provides

a tool to require tokens spendable only on the testnet.

This tool provides an amount of ﬁve AERGO, which

is more than necessary to build up our smart contract.

Aergo use a particular set up for Lua language, in-

deed the use of some default libraries like the ”os”

one is not allowed for security purposes, and it pro-

vides a type Map which is not of the original Lua.

This type, is like a Java Hash-Map but keys are al-

lowed to be only strings, while values are allowed to

be of any type.Inside the state.var scope we deﬁne

our global variables, and inside the constructor() we

set up variables.

As represented in Fig 2, on the left panel we can

notice the Athena-Ide interface, which is very simi-

lar to Remix environment for Solidity smart contracts

development. Indeed, we can see that is possible to

import an Aergo account, compile contracts and make

the contract deploy to append it on Aergo blockchain;

also, is possible to select if we want to work locally,

on test net or on main net.

3.4 The Document Timestamping

We now describe the implementation of a blockchain

based system for document timestamping we devel-

oped during the Document management project.

Given a document, we want to use the blockchain

to associate a timestamp to this document exploiting

the Aergo blockchain. The timestamp must be im-

mutable, so once the document is timestamped, it can

not be timestamped again.

In the following we describe functions and vari-

ables deﬁned in the implementation. In the Appendix

of this paper we we provide the complete source code

of our smart contract.

Global Variables. We used two global variables,

document prove and document id. document prove

is a Map type, and it stores the document id and the

associate timestamp. document id is an integer which

represents the document id.

Function set time. This functions should work

only if the one to call them is the owner of the con-

tract. Thanks to the ”system” library provided by

Aergo, we can call functions like getCreator() and

getSender() which allows us to make those types of

controls; so, if the contract is called by the owner we

can set a new document id.

As before, we check that owner and sender coincide,

and so if this is the case, we check that for a particular

document id a timestamp has not been associated yet;

if this is the case, then we associate a timestamp to

that document else we return an alert message.

Function get timestamp of a document. As ever

we check that the one which is calling the function is

the owner of the contract. If the owner is calling the

function then the associated timestamp to the docu-

ment id given in input will be returned. Else, if the

function is not called by the owner, an alert message

will be printed.

3.5 System Integration

As we said previously, Aergo provides SDK to inter-

act with the blockchain. Heraj is the library provided

by Aergo for Java language; this library allows to in-

terface Java with Aergo blockchain. This type of in-

teraction with Java and Aergo allows the development

of decentralized applications (dAPPs). Heraj makes

the development and the execution of smart contracts

very simple and efﬁcient. To use the library, we can

take the advantages provided by tools such as Gradle

(https://gradle.org/) or Maven (https://maven.apache.

org/). In the collaborative document management sys-

tem, the platform ALFRESCO is modiﬁed to include

the Heraj library. This allows the interfacing of the

software with the Aergo blockchain in order to use

the smart contracts deployed in it such as the times-

tamping one. To given an example, when we want

to modify a document, ALFRESCO could execute a

Blockchain Certiﬁcation and Granular Editing Permissions in Document Management System

303

Figure 2: The AERGO development platform for smart contracts.

smart contract using Heraj library and then, the con-

tract associate the block timestamp to the document

id to provide an incontrovertible date of the last doc-

ument changes.

By using Heraj it is possible to interact and even

to deploy a smart contract in the Aergo blockchain di-

rectly from the Java application. To connect the Heraj

library to our Aergo account we need all of our cre-

dentials (in particular we need our private key and our

decryption account) and we need an Aergo client in-

stalled.

4 CONCLUSION

In this work, we propose an innovative document

management solution built by using development

tools backed by large developer communities, with

the aim of ensuring the availability of adequate sup-

port during development. The architectural design

is being developed as a modular solution, due to the

need for integrating additional modular, interoperable

components, and built with open standards to make

the system ﬂexible. The prototype will try to effec-

tively tackle the complexities stemming from the in-

teraction of separate, interdependent processes. Spe-

ciﬁc services will have to work together with the pro-

posed solution, thus requiring to devise a proper in-

frastructure to meet users’ requirements as seamlessly

as possible. The system will ensure effective integra-

tion, and employ a cloud computing system (Lewis,

2012) (Rehman, 2018). The involved parties will ac-

quire new valuable knowledge on document manage-

ment, thanks to the cooperation network which will

stem from the development activities. The very na-

ture of the project itself is bound to ensure knowl-

edge sharing: being open-source, the project pro-

motes the intervention of external contributors, espe-

cially from individuals and organizations directly in-

terested in tackling their own business challenges with

the proposed solution. Among the innovative features

of the proposed document management solution, are

i) the possibility to assign speciﬁc access permissions

to each document section, and ii) document certiﬁca-

tion based on blockchain technology.

ACKNOWLEDGEMENTS

The work presented in this paper has been par-

tially funded by Regione Autonoma della Sardegna,

under projects “Gestione Documentale” - Progetto

PIA, Annualit

a 2013”, “Crypto-Trading” - Program-

mazione unitaria 2014-2020 POR FESR Sardegna

2014 - 2020, “Easy Wallet” - Programmazione uni-

taria 2014-2020 POR FESR Sardegna 2014 - 2020,

“SardCoin – SardCoin: tecnologie blockchain a sup-

porto del turismo in Sardegna” - TOP-DOWN POR

FESR sardegna 2014 – 2020 Asse prioritario 1, and

“CAFCha - Certiﬁcation of AgriFood Chain”- POR

FESR Sardegna 2014 – 2020 Asse 1.

The authors would like to thank Prof. Giovanni

Michele Pinna and Prof. Fabio Zuddas from Depart-

ment of Mathematics and Computer Science, Univer-

sity of Cagliari, Italy, and Prof. Alessandro Spano

from Dipartimento di Scienze Economiche ed Azien-

dali, University of Cagliari, Italy, for their helpful

comments and suggestions.

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APPENDIX

In this appendix we present the AERGO smart con-

tract source code written in LUA language for docu-

ment time stamping.

2 --Defining global variables

3 state.var

4 {

5 --Id of the document and map to

associat timestamp to document

7 document_id = state.value(),

8 document_prove = state.map()

10 }

12 function constructor()

13 --Setting up the constructor

14 --Currently the id 0 is reserved

15 document_id:set(0)

16 document_prove[tostring(document_id)] =

"RESERVED"

17 end

19 function change_id(id)

20 --getting owner and sender

21 owner = system.getCreator()

22 sender = system.getSender()

23 --This function is callable only by

the owner of the contract

24 if(owner == sender)

25 then

26 --Changing document

27 document_id:set(id)

28 else

29 system.print("YOU'RE NOT THE OWNER YOU

CAN'T ASSOCIATE TIMESTAMP TO DOCUMENT")

30 end

31 end

33 --Function to associate timestamp to a

document

34 function set_time()

36 owner = system.getCreator()

37 sender = system.getSender()

39 --Same as the previous function. Is

callable only by owner

40 if(owner == sender)

41 then

42 --If document has been already

timestamped is not modifiable

anymore

43 if(document_prove[tostring(document_id)]

== nil)

44 then

45 --Associating timestamp to

document

46 document_prove[tostring(document_id)]

47 = system.getTimestamp()

48 else

49 system.print("ALERT!!! DOCUMENT ALREADY

TIMESTAMPED. YOU CAN'T MODIFY IT")

50 end

51 else

52 system.print("YOU'RE NOT THE OWNER YOU

CAN'T ASSOCIATE TIMESTAMP TO DOCUMENT")

53 end

54 end

56 --Function to get timestamp of document

57 function get_timestamp_of_document(id)

58 --Callable only by owner

59 owner = system.getCreator()

60 sender = system.getSender()

61 if(owner == sender)

62 then

63 --Return the timestamp associated to

that document

64 return document_prove[tostring(id)]

65 else

66 system.print("YOU'RE NOT THE OWNER YOU

CAN'T ASSOCIATE TIMESTAMP TO

DOCUMENT")

67 end

68 end

71 --Setting on the Abi viewable functions

72 abi.register(set_time,change_id,

get_timestamp_of_document)

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