TrustLend: Using Borrower Trustworthiness for Lending on Ethereum
Wisnu Uriawan
1,3 a
, Youakim Badr
2 b
, Omar Hasan
1 c
and Lionel Brunie
Institut National des Sciences Appliqu
ees de Lyon, 20 Avenue Albert Einstein, Villeurbanne CEDEX, France
The Pennsylvania State University, Malvern, PA, U.S.A.
Department of Informatics, UIN Sunan Gunung Djati, Jl. A.H. Nasution No.105 Bandung, Indonesia
Blockchain, Ethereum, Lending Platform, P2P, Scalable, Trustworthiness Score.
The practice of personal lending, also known as Peer-to-Peer (P2P) lending, has been increasing globally.
However, providing unsecured loans to peers without requiring collateral remains a challenge. We present
a platform called TrustLend, which enables using borrower trustworthiness as an alternative to collateral in
personal lending transactions. TrustLend is a blockchain-based platform implemented on Ethereum. We
introduce a borrower trustworthiness score with variable selection rules to help lenders decide on reliable
candidates as borrowers. We describe the prototype implementation, which is a Decentralized Application
(DApp) that uses smart contracts. The prototype demonstrates fundamental features and supports borrowers,
recommenders, and lenders/investors in establishing loans and approvals. Finally, the prototype shows how
end-users can easily access loans with minimum collateral without hidden costs and swift transactions.
In general, micro-businesses and individual debtors
find it difficult to get loans from banks without ac-
cess to loan guarantors, and collateral (Pokorn
a and
Sponer, 2016). In P2P lending, borrowers directly in-
teract with peer lenders, making financing more ac-
cessible and efficient (Mammadli, 2016; Or
us et al.,
2019; Zhang et al., 2019) which means a higher credit
risk for lenders. Credit risk is the possible loss a bank
or other lender suffers after offering a loan to a bor-
rower. This includes the risk of the borrower default-
ing on the loan on time and the potential risk of de-
fault due to a decrease in credit score (Li et al., 2016)
or a reduction in the borrowers’ ability to repay.
P2P lending continues to increase worldwide ev-
ery year. For example, in 2013, it reached 3.5 billion
U.S. dollars. P2P lending is a new trend of the “shar-
ing economy” an exponential increase is estimated to
reach one trillion U.S. dollars in 2050. However, a
P2P lending platform can also create risks for lenders
when the borrower cannot make payments according
to the agreement. Trustworthiness (Bartoletti et al.,
2018; Kanagachidambaresan et al., 2012) is a critical
component in deciding for lenders whether borrow-
ers are accepted or rejected to get some loans. The
bank or financial institutions have taken many bor-
rower assets due to not fulfilling payments or expe-
riencing delays in payments. Blockchain technology
is emerging and successfully applied in many busi-
ness applications, such as banking and other financial
institutions (Larios-Hern
andez, 2017; Lee and Shin,
2018; Rana et al., 2019).
Blockchain technology encourages our motivation
to study the potential of the Ethereum blockchain
(Norta and Leiding, 2019). Recently, it has been ap-
plied in P2P and crowdfunding lending systems (Yum
et al., 2012). The benefit of this new technology has
led to explosive growth in the blockchain-based ap-
plication, which exists within a highly secure sys-
tem. Distributed ledger technology allows transaction
and problem settlement without third-party risk (Zhao
et al., 2017). The access to credit provided by the per-
sonal lending platform is intended to let the world of
blockchains grow beyond the economic limitations of
simply traditional money transactions. Loans (Cap-
ital, 2021; Zhao et al., 2017) is not only an impor-
tant economic factor, but they are also a vital compo-
nent of personal financial freedom and give individu-
als greater purchasing power.
This paper introduces TrustLend as a personal
lending platform Ethereum blockchain-based and
Uriawan, W., Badr, Y., Hasan, O. and Brunie, L.
TrustLend: Using Borrower Trustworthiness for Lending on Ethereum.
DOI: 10.5220/0011151900003283
In Proceedings of the 19th International Conference on Security and Cryptography (SECRYPT 2022), pages 519-524
ISBN: 978-989-758-590-6; ISSN: 2184-7711
2022 by SCITEPRESS Science and Technology Publications, Lda. All rights reserved
presents its fully functional prototype design and im-
plementation details. The paper builds upon our prior
research work (Uriawan. et al., 2021). We describe
the prototype architecture and conduct experiments
and various personal loans simulations. This paper’s
remainder is structured as follows: Section 1 intro-
duces the potential of a personal lending platform.
Section 2 related work. Section 3 is our proposal for
the trustworthiness prototype for a personal lending
platform. Section 4 implements the prototype and in-
put/output design. Section 5 discusses. Section 6 con-
cludes and future work of this paper.
Everex is a financial technology that creates decen-
tralized, global credit histories and scorings for indi-
viduals and Small Medium Enterprises. Everex sup-
ported enables transfers, borrowing, and trading in
any fiat currency from anywhere in the world. Its
Crypto cash Ethereum ERC20 token-based, regulated
by fiat currencies, is tradable on the Everex Wallet
and third-party applications and exchanges. Ethereum
provides distributed ledger system and incorporates
Turing-complete programming languages on the pro-
tocol layer to realize smart contract capabilities. It
is implemented on the Ethereum blockchain and uses
Solidity as a smart contracts language (Modi, 2018;
Norta and Leiding, 2019).
ETHLend is an Ethereum-based decentralized
lending platform worldwide connecting borrowers
and lenders. It allows anyone to lend or borrow
with an Ethereum address. ETHLend is decentralized
lending on the Ethereum network by using ERC-20
compatible tokens or Ethereum Name Service (ENS)
domains as collateral. ETHLend solves the problem
of reducing the loss of loan capital on default (Tran,
2019). WeTrust is an Ethereum blockchain to give
mutual aid equal footing with existing social capital
and trust networks. Trusted Lending Circles to create
a Rotating Savings and Credit Association (ROSCA)
powered by smart contracts. It eliminates the need for
a trusted third party, which cuts fees, improves incen-
tive structures, and decentralizes risks. It will even-
tually incorporate mutual insurance, voting within re-
ciprocal aid organizations, and P2P lending (Token,
This section presents the Trustlend architecture de-
scribing all functions, the lending platform proto-
type, trustworthiness score, and development princi-
ples. The architecture shows a DApp platform (Uri-
awan. et al., 2021) for Ethereum blockchain-based
personal lending to assist borrowers, recommenders,
and lenders/investors in the lending process.
This architecture minimizes or eliminates the
collateral need by assessing the borrower’s trustwor-
thiness score for the loan’s repayment users who
interact with the system as borrowers, recommenders,
and lenders/investors are shown in Figure 1.
Figure 1: Trustlend Architecture Design.
Smart contracts will handle trustworthiness scores,
recommendations, lenders/investors, and the wallet.
Borrowers’, recommenders’, and lenders’/investors’
transactions will be stored on the Ethereum
3.1 Trustworthiness Score
The trustworthiness score formula (Uriawan. et al.,
2021) is based on the user behavior attributes of risky
attitude, trustworthiness, time preference, and impul-
siveness (Arya et al., 2013). We adapt the trustworthi-
ness score formula in terms of the reliable borrowers
in Equation (1) and Equation (2). The trustworthiness
score that we propose is a value of borrowers set by
the smart contracts so that all parties (borrowers, rec-
ommenders, and lenders/investors) understand each
other’s obligations and risks that will be accepted.
The variables include loan risk, activity, profile, and
social recommendation.
Trustworthiness Score = Loan Risk score
+ Activity score + Pro f ile score
+ Social Recommendation score
Trustworthiness Score: Borrower Trustworthiness
Loan Risk score: Information of the record from
another loan of Borrower.
Activity score: Business activity or job information
of Borrower.
Profile score: Personal information of Borrower.
SECRYPT 2022 - 19th International Conference on Security and Cryptography
Social Recommendation score: The recommendation
value of Borrowers from Recommender.
and we added positive weight for each variable,
in equation 2:
Trustworthiness Score = w
Loan Risk score
+ w
Activity score + w
Pro f ile score
+ w
Social Recommendation score
where {w in R | w 1}, and w
, w
, w
, and w
positive weights of the trustworthiness parameters
such that w
+ w
+ w
+ w
= 1. The weights of the
trustworthiness attributes are predetermined based on
their priority value that can modify by consensus. For
example, w
= 0.25, w
= 0.2, w
= 0.25, w
= 0.3.
In this example, social recommendation is given the
highest value whereas activity is given the lowest
value it’s show that the social recommendation is the
priority to measure the good borrower candidate.
3.2 TrustLend Prototype Development
The prototype principles we adopt are standards codes
and conventions, automated units testing, and static
analysis tools. Some regulations relate to our proto-
type, as follows (Brown, 2013):
1. Layering strategy, the prototype applies a layers
strategy to make every design flexible for the bor-
rowers, recommenders, and lenders/investors.
2. Placement of business logic, our prototype en-
sures that business logic permanently resides in
a single place for reasons related to performance
or maintainability among the borrowers, recom-
menders, and lenders/investors.
3. High cohesion and low coupling, our prototype
focuses on building small, highly cohesive blocks.
There is no need to require many dependencies to
do their job. Part by part development related to
our prototype architecture design.
4. Use of the HTTP session, the prototype can of-
ten depend on many things, including scaling
strategy, where session-backed objects are stored,
what happens in the event of a server failure,
whether using sticky sessions, the overhead of
session replication,
5. Always consistent versus eventually consistent,
prototypes have discovered that it often needs to
make trade-offs to meet complex non-functional
Trustlend is the personal lending platform prototype
is a client-blockchain serverless application, where
the entire flow of the app happens between the client
and the blockchain. The client code can be hosted
anywhere, and Amazon Web Services with Sim-
ple Storage Service features, Google Cloud, Github
Pages, Netlify, other cloud providers, or own server.
Our prototype is able to query the blockchain, and we
use a web3 provider Metamask. A browser extension
handles the actual web3 connection to a node shown
in Figure 2.
Figure 2: Prototype of a Trustworthy Personal Lending
For example, all the business logic, loans, and
user history are handled and stored in the blockchain,
which is decentralized. However, the Ethereum
blockchain platform or any other Ethereum Virtual
Machines blockchain-based like Polygon charges fees
for each written transaction (Modi, 2018). We are
able to store the data not used in smart contracts cal-
culations to pay fewer fees, and choose the Interplan-
etary File System (IPFS) to store the loan descrip-
tion, images, and necessary data supported (Sicilia
et al., 2019). Once the data is stored in the IPFS, the
content identifier (CID) is returned and stored in the
loan smart contracts to find this data later. We use
NFT (Non-Fungible Token) (Buterin, 2014) storage
(Free, decentralized storage and bandwidth for NFTs)
to store the project’s info into IPFS.
4.1 Trustlend Smart Contracts
The main smart contract that the client interacts with
is the loan controller. It creates loans, handles invest-
ments, recommendations, repayments, etc. From the
moment the user applies for a loan, the apply for loan
function in the loan controller is called and creates
a unique loan contract related to the loan in ques-
tion. The smart contracts necessary of information
about the loan, including 1) Borrower (represented
by User contract instance), 2) Requested amount,
3) Repayment’s count, 4) Interest, 5) Loan creation
TrustLend: Using Borrower Trustworthiness for Lending on Ethereum
date, 6) Last repayment date, 7) Return amount, 8)
Lenders/Investors (array), 9) Recommenders (array),
10) Tscorecontroller contract (to handle user’s trust-
worthiness score).
The recommenders and lenders/investors can call
functions in the loan controller to lend/invest and rec-
ommend by providing the address of the loan con-
tract. These smart contracts require a communica-
tion process and are defined as a legal agreement
between borrowers, recommenders, and lenders/in-
vestors shown in Figure 3.
Figure 3: Smart Contracts Trustworthiness score.
4.2 Lending Transaction Process
The Trustlend is built on React framework, an open-
source javascript library. The application the criti-
cal main pages, The prototyping functionality is of-
fered to three users: Borrowers, Recommenders, and
Lenders/Investors. The borrower can access their
menu on the borrower page. Before accessing the pro-
totype, they (Borrowers, recommenders, and Lender-
s/Investors) should have the Metamask wallet and lo-
gin. After the loan application has been received, the
borrower user can make installment payments accord-
ing to the agreement.
The lenders/investors user can access their menu
and lend/invest with a selection of borrowers who
propose the loan. In these cases, the lender/investor
user determines the allocation of funds for the de-
sired. The recommenders user can access the recom-
mendation score menu to give each borrower a recom-
mendation score and amount of funds (in ETH for-
mat). The lenders/investors use the trustworthiness
score to decide and grant the loan. The main page
Figure 4: Trustlend main page.
provides a menu for borrowers, recommenders, and
lenders/investors, is shown in Figure 4. Users can ac-
cess it after being connected to their Metamask wal-
let. The Trustlend combines trustworthiness score and
consensus in a legal agreement among the borrowers,
recommenders, and lenders/investors. Users obtain
permission only, such as security, immutability, and
ledgers that can be changed through the consensus.
Metamask wallet is required by prototype, and
users can install individual with terms and conditions
shown in Figure 5 (a). Users manage the private key
to receive the payments per transaction by their wal-
lets. Unsigned transactions are sent from the wallet to
the Trustlend for other payments transactions and ver-
ified by the borrowers, recommenders, or lenders/in-
vestors. The personal wallet screen is confirmed via
Metamask as third-party, then approved by the user
4.2.1 Borrower Page
The borrowers can access the prototype in Figure 5
(b). The system provides how the borrowers propose
SECRYPT 2022 - 19th International Conference on Security and Cryptography
(a) (b)
Figure 5: Trustlend Metamask Wallet (a) and Trustlend
Borrower Request a Loan (b).
some loans with terms and conditions. Some users
give some loans information, and signals are sent to
all recommenders and lenders/investors. The bor-
rower page is provided to borrowers when trying to
apply for some loans, with the proposed loan amount,
installment period, and loan description being the pur-
pose of the loan.
4.2.2 Recommender Page
The recommender can access the Trustlend with their
wallet. Trustlend will provide the borrowers who
need recommendations. Then the recommenders give
some ETH and score/value see in Figure 6 (a). The
Trustlend provides the recommendation page to en-
sure the lenders/investors can grant the loan.
(a) (b)
Figure 6: Social Recommendation score input (a) and
Lender/Investor page input (b).
4.2.3 Lender/Investor Page
The lender/investor page is for lenders/investors look-
ing for eligible borrowers. This page includes infor-
mation on borrowers, loan amount, and interest in
APY (Annual Percentage Yield) see in Figure 7. It
is possible to be customizable between borrowers and
lenders. The system will present borrowers who pro-
posed a loan. The lenders/investors will get an oppor-
tunity with several borrowers’ prospects, is shown in
Figure 6 (b).
The smart contracts as a legal agreement (Borrow-
ers, Recommenders, and Lenders/Investors sides) are
the core of the lending prototype we are proposing.
The excellent trustworthiness score of borrowers is a
significant factor in this lending prototype. Reduc-
ing collateral dependence is replaced by social recom-
mendation. Many lending platforms and banks still
require a guarantee, which is burdensome for the bor-
rower to provide.
4.2.4 Summarize the Loan Request
The borrower loan information describes the loans
proposed for each borrower, including the amount
requested, lenders/investors information, recom-
menders, trustworthiness score, collateral in crypto/-
token, and interest. It is reasonable to expect a high
credit score associated with the payments process, is
shown in Figure 7.
Figure 7: Trustlend Borrower Request a Loan.
The objectives of this prototype are to avoid impul-
sive borrowers who have difficulty resisting the temp-
tation to borrow and increase debt for consumptive
needs. Lenders/Investors are able to monitor the bor-
rower and manage their lend/investment by choos-
ing eligible borrowers to minimize their losses. Each
lender/investor can choose by determining borrowers
who can pay off and get the highest trustworthiness
score. The trustworthiness score formula is well de-
fined (such as weight percentage, variables, etc.), and
is not possible to change after deployment.
Blockchain technology has advantages with im-
mutability, integrity, and equal rights for all net-
work members to get some information, and protect
users’ data from unauthorized access and encryption.
TrustLend: Using Borrower Trustworthiness for Lending on Ethereum
There is no personal information of borrowers, rec-
ommenders, and lenders/investors shown. We provide
a prototype with an autonomous transactions process
supported by smart contract functions after deploy-
ment. Smart contracts pay attention to borrower trust-
worthiness scores on a personal lending platform so
that lenders can consider the potential risks that will
be incurred. The value of trust among borrowers, rec-
ommenders, and lenders has a strong influence on a
personal lending platform.
The disadvantages are that performing off proto-
type transactions will increase transaction time be-
cause the need for recommendation score and granted
from lender/investor must be approved. In particular,
all users are aware of the risk and the borrower’s trust-
The Trustlend is a prototype of trustworthy Ethereum
blockchain-based for personal lending that can pro-
vide a loan for borrowers who need without collat-
eral. The social recommendation as a guarantor to
convince lenders/investors to grant the loans to bor-
rowers. This prototype is one of the lending platforms
suitable for personal lending applications that apply
blockchain advantages dimensions: anonymous, de-
centralized, immutability, and secure. This prototype
proposes to minimize the difficulty by introducing the
trustworthiness score to support borrowers, recom-
menders, and lenders/investors. The Trustlend is ex-
pected to be implemented in private environments that
can be scalable to many members possible.
The first author wishes to acknowledge the MORA
Scholarship from the Indonesian Government and
INSA de Lyon LIRIS Laboratory UMR 5205 CNRS,
which partially supports and funds this research work.
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