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A Secure and Practical Decentralized Ecosystem for Shareable Education Material

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Abstract

Traditionally, the university landscape is highly federated, which hinders potentials for coordinated collaborations. While the lack of a strict hierarchy on the inter-university level is critical for ensuring free research and higher education, this concurrency limits the access to high-quality education materials. Especially regarding resources such as lecture notes or exercise tasks we observe a high susceptibility to redundant work and lacking quality assessment of material created in isolation by individual university institutes. To remedy this situation, in this paper we propose CORALIS, a decentralized marketplace for offering, acquiring, discussing, and improving education resources across university borders. Our design is based on a permissioned blockchain to (a) realize accountable access control via simple on-chain license terms, (b) trace the evolution of encrypted containers accumulating bundles of shareable education resources, and (c) record user comments and ratings for further improving the quality of offered education material.
A Secure and Practical Decentralized Ecosystem for
Shareable Education Material
Roman Matzutt, Jan Pennekamp, and Klaus Wehrle
Communication and Distributed Systems
RWTH Aachen University, Germany
{matzutt, pennekamp, wehrle}@comsys.rwth-aachen.de
Abstract—Traditionally, the university landscape is highly fed-
erated, which hinders potentials for coordinated collaborations.
While the lack of a strict hierarchy on the inter-university level
is critical for ensuring free research and higher education, this
concurrency limits the access to high-quality education materials.
Especially regarding resources such as lecture notes or exercise
tasks we observe a high susceptibility to redundant work and
lacking quality assessment of material created in isolation by
individual university institutes. To remedy this situation, in
this paper we propose CORALIS, a decentralized marketplace
for offering, acquiring, discussing, and improving education
resources across university borders. Our design is based on a
permissioned blockchain to (a) realize accountable access control
via simple on-chain license terms, (b) trace the evolution of en-
crypted containers accumulating bundles of shareable education
resources, and (c) record user comments and ratings for further
improving the quality of offered education material.
Index Terms—blockchain platform; permissioned blockchain;
education material; quality assessment; collaborative work
I. INTRODUCTION
Author manuscript.
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2020 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including
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reuse of any copyrighted component of this work in other works. DOI: 10.1109/ICOIN48656.2020.9016478
While universities have the common goal of providing
high-quality education to form young experts, the university
landscape is inherently federated and even a competitive envi-
ronment regarding publications and available funding sources.
This competitive aspect of research puts the modern university
landscape under high pressure [1] and thus researchers find
themselves in a dichotomy: A certain level of collaboration
among mutually trusting institutes proves profitable to gain
high-quality insights, but avoiding tight collaborations out of
the fear of losing a lead over competitors has also been es-
tablished as a rational approach. This dichotomy is especially
apparent when taking the universities’ duty to educate into
account. Currently, there exists no clear incentive for univer-
sities to collaboratively create or improve education resources,
such as lecture notes, slides, or exercise tasks. This status quo
introduces a major drawback: Similar education material is
frequently being created and maintained redundantly across
different institutes, potentially even within one university. If
institutes could instead invest this time into improving each
others’ education resources, we see a great potential for creat-
ing high-quality and highly vetted pools of education material
from which all students could benefit equally. While individual
contractual collaborations across university institutes [2] and
education repositories of varying focuses [3] exist, those
isolated approaches cannot unveil the full potential of globally
available high-quality education material. However, a versatile
range of education prospects is critical to properly prepare
students and seize creative opportunities. Yet, these aspects
are threatened by strong centralization in education [4].
Hence, in this paper we propose to create a decentralized
ecosystem that incentivizes the collaborative creation, main-
tenance, and improvement of education resources. Distributed
ledgers such as blockchain systems provide the means to create
such an ecosystem despite the inherent trust barriers regarding
inter-university collaborations. Popularized by Bitcoin and
Ethereum, distributed ledgers constitute a general medium for
the secure and accountable interaction of mutually distrusting
parties [5], [6]. Our proposed blockchain-based platform,
CORALIS, serves as a decentralized index of available educa-
tion resources, provides a marketplace with accountable access
control for these resources, and incentivizes collaboration
across university borders to improve them. To achieve these
desired properties, CORALIS relies on immutably recording
all relevant events on its underlying permissioned blockchain:
First, material providers, who can either be university teachers
or accepted third-party content creators, announce new educa-
tion resources in conjunction with simple and tunable license
terms to the platform. Subsequently, users, i.e., other university
teachers, interested in buying this material have to perform
an on-chain handshake beforehand that immutably records
both parties’ mutual agreement to trade the material under
the specified license terms. Finally, participants collaboratively
improve existing resources by rating them, discussing flaws or
improvements, and proposing improved versions of existing
material, either to resolve issues or to provide extensions.
Contributions. We make the following main contributions
to improve inter-university collaborations for creating and
sharing education material in a practical and secure manner.
We identify the need for a decentralized and transparent
platform to enable universities to collaboratively maintain
education material across university borders as well as the
open challenges for such a ecosystem.
We propose CORALIS, a design for a practical
blockchain-based platform that enables material providers
to securely share their material.
We discuss approaches for licensing shareable education
resources, especially regarding the increased flexibility of
integrating obtained resources into existing local reposi-
tories of education material.
II. ON T HE NE ED F OR A BLOCKCHAIN-BAS ED
ECO SY ST EM TO MANAG E EDU CATION MATERIAL
To motivate the need for a blockchain-based management
system and market for digital education resources, we first
discuss our assumed scenario and subsequently derive re-
quirements and design goals for creating such a system that
especially take security and practicality into account.
In a traditionally highly federated field, collaborations be-
tween universities are seldom. In this work, we seek to remedy
this situation and note the following observations as a founda-
tion for our proposed ecosystem. We envision a collaborative
network consisting of interconnected university institutes and
third-party content providers with a dedicated representative;
the organization within a single institute is out of the scope of
this work. Institutes are obligated to educate students and thus
maintain a local repository of educational resources. Education
resources may be diverse, i.e., they encompass lecture notes,
slides, exercise and exam tasks.
We acknowledge that the creation of education material,
i.e., a collection of education resources, may become bur-
densome without immediate payoff in perspective. Following
the observed behaviors of users of peer-to-peer file sharing
platforms [7], we thus assume an asymmetry regarding the
demand and provision of educational material. While we
anticipate few heavy material providers, most institutes are
mere users, although any institute may assume both roles
simultaneously with varying shifts towards either extreme.
To avoid free-riding [8] of users, we must provide suitable
incentives to actively contribute to the community.
However, material providers demand keeping control over
their original education resources to be willing to share their
material with other institutes which are potentially unknown
to them. On the one hand, they must be able to decide whom
to grant access to certain education resources to maintain con-
fidentiality, e.g., considering highly specialized and research-
oriented material. This condition implies that they must be
able to maintain fine-granular access control. On the other
hand, if an institute decides to conditionally share its education
resources, the system must assure that users respect the terms
of use, e.g., properly attribute the work’s original source.
Finally, providing financial compensation for an institute’s
efforts would further incentivize active contribution of new
material or improvements.
Based on this scenario, we derive the following design goals
for an ecosystem facilitating the collaborative management of
education material across universities and their institutes.
(G1) Access Control and Accountability. Material
providers must be able to decide whom to grant access to
which of their education resources. Furthermore, they must be
able to specify the fee for utilization, i.e, the price, and license
terms associated with their work. Conversely, users must be
able to browse accessible education resources to decide which
material they want to request. All access-granting decisions
must be recorded in a tamper-proof log to introduce account-
ability and liability for both material providers and users.
(G2) Collaborative and Transparent Improvements. The
Blockchain-based Marketplace
for Education Material
Material Repository
Material Provider User
1. Create
2. Offer 3. Request
4. Accept
5. Leverage
7. Share 6. Improve
Material Repository
Fig. 1. Overview of our proposed blockchain-based platform for the
collaborative maintenance of education material across university borders
according to the CORALIS workflow: Material providers create and offer
education resources for users to request. After the material provider accepted
that request, the user may leverage it according to its terms of use. In a tit-
for-tat manner, the user can subsequently improve the obtained material and
share it again with the community.
whole evolution of education material should be recorded in a
transparent manner to enable participants to track changes and
updates for specific education resources, effectively introduc-
ing a variant of version control. This requirement encompasses
logging all traces of improvements to individual resources as
well as recording comments and questions from users.
(G3) Efficient and Sensible Storage Model. While ma-
terial providers require that all developments are immutably
recorded, we also acknowledge that education material must
be revocable. Furthermore, the distributed nature of local
repositories of each material provider must not hinder the
accessibility of data (for external users and collaborators).
This requirement is especially crucial when external users
contribute to existing education material stored in a local
repository under the control of a single material provider.
Next, we discuss our proposed approach for creating a
blockchain-based platform to achieve these design goals and
discuss challenges arising from our approach.
III. A BLOCKCHAIN-BA SE D MAR KE TP LACE FOR
EDU CATI ON MATE RI AL
In this section, we first provide an overview of our proposed
blockchain-based platform for collaboratively managing edu-
cation material. Subsequently, we discuss how our platform
can achieve accountable access control. Besides, we highlight
challenges for the distributed storage of education material
considering a potentially large number of collaborators.
A. Design Overview
We base our blockchain-based platform, CORALIS, on a
general workflow for the collaborative maintenance of educa-
tion material. We illustrate the seven steps of this CORALIS
workflow in Figure 1 and introduce them in the following.
Material providers first Create a repository of education
resources. Then, they can choose to Offer selected material
to other institutes, who then assume the role of users. All
offered resources are announced on CORALIS’ underlying
permissioned blockchain, which is maintained collectively by
material providers and users. Consequentially, each institute
can create a local index of available education resources,
Material
Container
Bundle M1Type: Offer
TX ID: txoff,1
User: Bob
Loc:ID1= H(M1)
Meta:(L1, P1, T1)
Wit:Hmac(k, ID1)
Announce
New Material
Type: Request
TX ID: txreq,1
Prev:txoff,1
User: Alice
Price: P1
Request
Access
Type: Accept
TX ID: txacc,1
Prev:txreq,1
User: Bob
Auth:Enc(Alice, k)
Accept
Access Request
Type: Complaint
TX ID: txcpl,1
Prev:txacc,1
User: Alice
Wit: k‘
Optional: File
Complaint
k
Slide Set
Notes
Tasks
Exam
Fig. 2. We propose an on-chain three-way handshake for accountable access control that enforces education resources to be released only after the user
irrevocably accepted the material provider’s license terms and price asked. First, the provider offers new material in conjunction with relevant meta information.
Then, users can request to access or purchase offered resources, thereby committing to abiding to their license terms. Finally, the provider accepts the request
and simultaneously provides the user with the symmetric key required to access the purchased resources. If the user is cheated, e.g., she receives a wrong
symmetric key, she can file an on-chain complaint to blame the misbehaving provider.
effectively establishing a marketplace for education material.
To acquire desired material in an accountable manner, a user
has to Request specific resources via an on-chain transaction,
which the material provider has to explicitly Accept on-
chain in return. After recording this mutual agreement on the
blockchain, the user may obtain and Leverage the acquired
material from the material provider. To contribute to the
community in a tit-for-tat manner, the user can subsequently
Improve the material and Share an updated version with
the community. Improvements can either consist of changing
education resources or discussing their content. Similar pro-
cesses are well-established on platforms such as GitHub [9].
Furthermore, ratings reflect resources’ perceived quality.
In the following, we first detail how CORALIS realizes
accountable access control (Goal G1) and discuss challenges
for keeping track of material improvements (Goal G2) as well
as the distributed storage of education material (Goal G3).
B. Achieving Accountable Access Control
Figure 2 illustrates our approach of recording a three-way
mutual agreement on the blockchain to address Goal G1,
i.e., to achieve accountability and access control. Material
providers keep all their education resources or compiled bun-
dles thereof in individual, symmetrically encrypted material
containers. This design ensures that the original provider
remains in control over their resources even if the storage
of material containers is outsourced to a third party as they
can decide whom to disclose the symmetric key kto. To offer
material to users, the provider publishes an offer transaction
toff to the blockchain, including an identifier of the material
container, meta information that determines the license terms
Lin a concise form, the price P, and additional index tags
T, and a witness of the container’s validity.
The witness is needed if disputes between providers and
users arise whether or not access has been granted correctly.
It consists of an HMAC constructed over the container’s
identifier using the symmetric key k. By publishing a request
transaction treq referring to toff, a user signals her interest
in obtaining the material while simultaneously committing to
paying the price Pand abiding to the license terms L. The
provider has to accept this request via an accept transaction
tacc, which provides the user with the key krequired to access
the material container’s contents. CORALIS makes the whole
mutual agreement process publicly verifiable to increase the
detectability of misconduct.
However, the provider could try and provide the user with
a wrong key k0to prevent her from accessing the material
regardless of her payment. To avoid this pitfall, users can file
an on-chain complaint against the provider’s tacc. By disclosing
her received key k0in case of a dispute, the user can prove that
the provider indeed shared k0in tacc and she can prove that
the validity witness of toff does not match k0. Unfortunately,
this approach cannot prevent the provider from constructing
a meaningless material container in the first place. We thus
propose to mitigate the impact of this inherent issue, which
is known from content-offloading scenarios [10], by allowing
users to post short and public on-chain ratings.
C. Transparently Storing Distributed Education Material
We now discuss challenges regarding storage requirements
(Goal G3). We first discuss how to integrate the potentially
large number of contributors for one material container into
our system and then consider different storage models.
CORALIS must efficiently link multiple user contributions
to the same education resource while respecting its confiden-
tiality against users without access permission. In Figure 3,
we detail how we integrate comments and improvements
to education resources into our system. To keep education
resources self-contained, we append comments addressing
them to their respective material containers, encrypted via the
same key k. However, comments are referenced on-chain as
well to maintain transparency (Goal G2). We refrain from
storing arbitrary user-generated data on-chain due to potential
negative and hard-to-resolve side effects [11], [12]. With this
approach, all relevant information for one material container
Material Container M1Material Container M2
à
1
M1
C1,1
C1,2
C1,3
M2à1
C2,1
C2,2
Blockchain
Task: What is 7 and 3?
Solution: 15
Do you rather mean 10?
Please, be more formal.
Oh, right! Sorry!
Comments:
Task: Solve 7 + 3 = ?
Solution: 10
Ah, much better!
Should calculators be
permitted for this task?
Comments:
Adapted from: M1
Fig. 3. The blockchain of our CORALIS platform constitutes an immutable
ledger of the evolution of education resources that are stored off-chain.
Provider UserBlockchain
(a) Local Storage
Provider UserBlockchain
(b) Cloud Storage
Provider UserBlockchain
(c) Distributed Storage
Fig. 4. Encrypted material containers enable providers take various approaches to persistently storing their material. CORALIS is compatible with (a) local
per-provider repositories of education resources, (b) a centralized storage outsourced to, e.g., a public cloud, and (c) fully decentralized storage architectures.
can be obtained from a single source while the blockchain
attests the container’s integrity. Improvements, however, are
stored in a new material container that only references the
parent material container for transparency reasons. We chose
this design to better suit the users’ requirements of managing
their (improved) education resources locally. Yet, as shown
in Figure 4, our utilization of encrypted material containers
also allows outsourcing their material containers securely to
public clouds or a fully distributed storage to further address
Goal G3.
IV. IMMUTABLE LICE NS E TER MS FOR SHAREABLE
EDU CATI ON MATERIAL
After describing our design for the CORALIS platform, we
now focus on the aspect of how material providers and users
can collaboratively utilize this ecosystem (Goals G1 and G2).
To this end, we first discuss how material providers can express
license terms in Section IV-A. Subsequently, we elaborate
on questions a license model must cover in our context in
Section IV-B. Finally, we discuss the degrees of enforceability
and challenges of disputes in Section IV-C.
A. Standards for Secure and Immutable License Agreements
As discussed in Section III-B, material providers must
specify license terms when offering new material and users can
only obtain material after immutably committing to abiding
to these terms on CORALIS’ blockchain. We now further
discuss the requirements for expressing license terms in our
context, outline an approach to implementing licensing terms
in CORALIS based on these requirements, and identify aspects
stemming from considerations regarding both usability and
technical applicability.
Completeness. The specification of license terms must
cover all relevant questions for any given type of education
material to allow material providers to express their intended
usage terms. This aspect is especially relevant for collabora-
tively created material.
Simple Formulation. CORALIS is intended to be a mar-
ketplace for quick and easy access to education material.
To support this intention, license terms should be presented
to interested users browsing available resources in a simple
form to ease their comprehensibility. Consequently, all desired
license terms should be easily expressible.
Concise Representation. As discussed in Section III-B,
license terms must be strictly tied to a purchase and, therefore,
they are included in the on-chain handshake between material
providers and users. Hence, license terms ideally should allow
for a concise on-chain representation.
Intuitively, these technical requirements contradict the us-
ability considerations. When giving material providers more
decision parameters when specifying license terms and re-
quiring those terms to be expressed comprehensibly for users,
these license terms inevitably gain a certain verbosity. This
observation stands in contrast to our requirement for concise
on-chain license terms. However, we can resolve this conflict
by creating a license chooser for CORALIS as implemented
for, e.g., End-User License Agreements (EULAs) [13] or
resources for the public domain under the Creative Commons
licenses [14]. A license chooser allows material providers
to easily specify their license terms by answering a few
questions and generating their final representation based on
the submitted decisions. Hence, we only need to store the
material provider’s decisions on-chain to be parsed in a com-
prehensible form for interested users. To this end, the compact
privacy policy language CPPL [15] promises to constitute a
well-suited building block for CORALIS. CPPL was initially
designed to enable owners of potentially sensitive data to
attach compressed privacy policies to their data items before
outsourcing them, e.g., storing them within a public cloud.
The compression of CPPL is especially efficient due to its
incorporation of domain-specific knowledge [15]. Thus, an
adaption of CPPL’s underlying compression scheme to express
CORALIS’ license terms is a very promising approach to
fulfill the identified requirements of completeness, simplicity,
and conciseness.
B. Considerations for a Comprehensive License Model
We now briefly present initial questions our license chooser
needs to incorporate to provide a suitable licensing model. We
identify the following fundamental specifications our license
model must be able to express.
Target Audience. While we envision CORALIS to establish
an open marketplace within the boundaries of the academic
context, material providers still need to be able to exclude
certain users from obtaining their resources. For instance,
material providers may disallow any utilization that directly
facilitates preparing students for research in military contexts.
Attribution. Material providers must be able to enforce
proper attribution of their original works to establish a non-
monetary incentive for creating material. Attribution terms
can, e.g., require to name the original author, her affiliation,
or funding sources in the context of an education resource.
Furthermore, varying levels of required attribution can be
specified, such as a copyright notice on each lecture slide,
or once on a dedicated slide, or no attribution at all.
Scope of Dissemination. A material provider must be able
to restrict the dissemination of her work to prevent its uncon-
trolled multiplication. For instance, she can choose to allow
certain fundamental exercise tasks to be freely distributed
online, while advanced exercises must only be distributed in
paper form among students attending a course.
Allowed Modifications. Finally, material providers can
grant certain rights to modify purchased resources. Especially
regarding the form of required attribution, unintended or poor
modifications of education resources gain the potential to harm
the original provider’s reputation. Dealing with modifications
of original work is a fundamental aspect for licensing of open
source software [16], hence we envision that we can further
seize experiences from that domain for our licensing model.
This initial framework serves as a foundation for future
considerations as CORALIS’ final licensing model will need
to remain more tunable to address even complex situations.
C. Handling Licensing Disputes
After specifying the requirements for a licensing model, we
now discuss to which extent CORALIS can help participants
to resolve disputes over potential violations of license terms.
Specifically, we argue that license terms cannot be technically
enforced and that material providers and users have inherently
conflicting interests. While material providers seek to protect
their original work to the largest extent possible, users and
their students can benefit from more relaxed terms of use.
Fundamentally, CORALIS cannot provide full enforceabil-
ity of license terms since various forms of misconduct are hard
to globally observe, monitor, or stem. For instance, users and
students can collude to distribute education resources among
each other that were only meant for presentation during a
lecture. Similarly, students can make unauthorized copies of
such resources. However, our platform transparently records
each user’s commitment to abide by the terms and therefore,
potential violations can be investigated publicly against the
license agreements. A related approach to public verifiability
is already implemented, e.g., when publicly showing sports
events without commercial subscriptions, where the broad-
caster requires viewers to report any observed misconduct [17].
To support the identification of license violations, mate-
rial providers need to enrich their resources with indicators
reflecting permitted use. Referring to our previous example,
permitted public transmissions of proprietary content can be
indicated by small overlay icons [17]. A similar approach can
be implemented to enable students to verify permitted use of
shown resources, for instance by displaying QR codes in con-
junction with the presented resource that link to the publicly
verifiable mutual agreement within CORALIS’ blockchain.
Furthermore, material providers can make use of cryptographic
means, such as Digital Rights Management (DRM) [18], to tie
digital resources to their respective license terms.
This restrictive approach, however, stands in stark contrast
to the interests of users and their students. Disallowing modifi-
cations to education resources and technically hindering such
modifications can ultimately enable large material providers
to essentially re-centralize the market for offered material [4].
Consequently, few global players would be enabled to effec-
tively steer higher education. Actively encouraging certain
levels of mutability, however, has the potential to greatly
improve the experiences of both users and their students. For
example, we consider education resources that are available
in an appropriate standardized text format (e.g., L
A
T
E
X code)
in small, self-contained chunks. This format enables users to
seamlessly integrate these well-vetted education resources into
their own material and thereby (a) successively and selectively
increase their material’s quality, (b) present material in a
unified look and respect, e.g., corporate design requirements,
and (c) tailor material to their students’ needs. To illustrate the
need for adapting education resources, consider the notation
of complex numbers as a simple example. In mathematics,
the imaginary unit is typically denoted by i, while jis used
in electrical engineering to avoid confusion with currents. By
enabling users to easily adjust such notation, they can effort-
lessly combine high-quality material from different sources.
Hence, especially a simple adaptability of education resources
promises great benefits for users and their students.
Even though CORALIS does not position itself explicitly
within this trade-off between protecting original work and
easing adaptability, disputes will likely arise over potential but
not explicit violations of agreed-upon license terms. As already
indicated, such disputes cannot be decided automatically in all
cases, hence we need to address the question of how to deal
with these situations on a completely decentralized platform.
To this end, we propose to enhance the on-chain complaints
of CORALIS (cf. Section III-B) such that material providers
can also file complaints after a successful initial agreement to
indicate alleged misconduct by users. However, our decentral-
ized platform does not designate a dedicated party to resolve
disputes based on these complaints. Instead of requiring all
participants of CORALIS to redundantly investigate on-chain
violation claims, we instead propose to adapt SmartJudge [6],
a general-purpose framework for dispute resolution on public
blockchains, for use in our ecosystem. Specifically, Smart-
Judge considers that interacting parties can mutually agree on a
tie-breaking instance in case of a dispute. A slight adaption of
this approach enables material providers and users to outsource
the dispute resolution to a small mutually accepted jury of
CORALIS participants to unburden the remaining participants.
In conclusion, CORALIS bears a high potential for exchang-
ing education resources among mutually not fully trusting
participants by providing an immutable and publicly verifiable
distributed ledger of agreed-upon license terms. However,
whether material providers decide to distribute their education
resources in a more restrictive or adaptable manner currently
remains an open question and will likely influence future
business models involving CORALIS. Our platform addresses
this issue through its general-purpose material containers (cf.
Section III-B), hence material providers can distribute their
material with varying degrees of technical protection.
V. RE LATE D WOR K
CORALIS is related to work considering blockchain data
storage, distributed version control, and blockchain platforms
facilitating social interaction or education processes.
Currently, education resources are shared either based on
contractual agreements and commitments [2] or via isolated
teaching repositories [3]. While definitively providing a step
toward increased levels of collaboration, both approaches
suffer from a rather narrow scope regarding the availability of
vetted education resources. To maximize the benefit of high-
quality education resources, inspired by the concept of data
markets [19] and blockchain-like approaches to distributed
configurability [20], we instead rely on a blockchain platform
that is open to known material providers and users.
This choice raises questions regarding blockchain-backed
storage models. We have previously shown that on-chain con-
tent storage can have devastating consequences for the whole
ecosystem [11]. Hence, other approaches using a blockchain-
based storage typically rely on tying their data to immutable
on-chain evidence [21], [22], [23]. We share this general
pattern with other blockchain-based platforms that realize,
e.g., decentralized social networks [24] or a blockchain-based
consistency check for mirrored software packages [25].
Combining and extending these promising applications,
CORALIS facilitates the rating, discussion, and collabora-
tive improvement of education resources. Related work also
identified various benefits for blockchain platforms in educa-
tion [26], for instance, for purposes of immutably recording
student achievements [27], but also managing intellectual
properties [26]. However, to the best of our knowledge,
CORALIS is the first proposal to implement such a platform
as of now regardless of its focus on the academic landscape.
VI. CONCLUSION AND FUTURE WO RK
In this paper, we motivated the need for a blockchain-
based inter-university platform to facilitate the collaborative
creation and improvement of high-quality education resources
to effectively avoid redundant work. Our design focuses on
material providers who should remain in control and on the
establishment of accountable on-chain license agreements that
are publicly verifiable via our CORALIS blockchain. We
discussed the need for simple and concise license terms in
our system and proposed to combine a simple-to-understand
license chooser with a space-efficient policy language. Finally,
we argued that technical means to report violations of license
terms exist to resolve arising disputes within CORALIS.
Future work for CORALIS involves additional research
into applicable business models, e.g., to properly reflect
the trade-off between resource protection and flexibility in
a resource’s value or to further incentivize reviewing and
improving existing education resources. Besides, we aim to
evaluate the scalability limits of our proposed platform by
deploying a proof-of-concept implementation. We plan to
realize this implementation via established building blocks,
such as Hyperledger Fabric for the blockchain backend of
CORALIS, CPPL for our license agreements, and suitable
data formats for expressing well-protected as well as highly
adaptable education resources. Further, we see a potential for
CORALIS to create an ecosystem among commercial software
developers, i.e., to offer properly licensed, high-quality code
fragments for recurring patterns.
ACKNOWLEDGMENTS
This work has been funded by the German Federal Ministry
of Education and Research (BMBF) under funding reference
number 16DHLQ013. The responsibility for the content of this
publication lies with the authors. Further, the authors thank
Erhard Cramer and Roberto Bernardo for the discussions.
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