Alior Bank: a durable medium solution developed with Ethereum public Blockchain.

First in Poland implementation of public Blockchain in a banking sector that solves a durable medium issue.

About the Client

Alior Bank SA is a universal bank and the 10th largest financial group in Poland with more than 6 000 employees and over 108 mln PLN net income for Q1 2021.

It is a highly innovative institution that implements technological solutions including Blockchain. Alior Bank together with the largest regional insurance company, PZU runs a tech accelerator for FinTech startups - RBL_Start.




Ongoing, since 2019




Blockchain implementation

Company size


The Durable Medium Issue for Financial Sector

European Law enforces companies that enter into distance contracts to meet broad regulations. One of the requirements is delivering to customer terms and conditions, pricing tables and tariffs, etc. in a form of a ‘durable medium’. A traditional form of such medium was printed documents usually delivered by post. Digital transformation of businesses opened paths to change this practice and use websites and dedicated urls. The question was dedicated URLs are ‘durable’? That was addressed by courts that defined dedicated urls as not meeting formal requirements. Respecting legal requirements companies and financial institutions must guarantee a truly Durable Medium.

Blockchain technology is an answer to the problem.

Looking for an execeptional FinTech & Blockchain developers for your project?

Estimate Project

Alior Bank’s Challenge

Alior Bank, likewise all banks in European Union, is obliged to deliver to their clients' commercial information in an imperishable and unalterable form. One of the forms was on paper by post. In the case of Alior bank, it is over a million paper letters annually.

The bank designed a solution to meet two requirements:

  • deliver reliable Durable Medium in a form of documents visible on Blockchain ledger,

  • become paperless and more eco-friendly.

For those reasons, Alior Bank sought a FinTech and Blockchain technology partner that will deliver integration of Ethereum Blockchain with Bank’s online service and in the long run maintain the solution.

The Bank’s requirements for the project and the technology partner:

  • A team of the best experts in FinTech and Blockchain in the CEE

  • Compliance with bank’s formal requirements i.ex. Business Continuity Management Plan

  • Meeting bank’s IT security requirements

  • Service availability and scalability

  • Delivery time

  • Communication fit

A corporate verification process

Alior Bank selected Nextrope as a technological partner which proves Nextrope’s both organizational and technological readiness to work with the most demanding brands.


Since 2019 Nextrope maintains the service within strict SLAs and performance requirements.

Transparent and resilient Durable Medium

Nextrope has delivered the API, in a SaaS model, allowing Bank to publish transactions on the public Ethereum network.


The project is 100% compatible with the bank's most rigorous IT security requirements.

“Polish Bank Alior uses Public Ethereum Blockchain For New Document Authentication Feature”


The Blockchain Solution

Nextrope’s team has developed and provided an online service for block-sharing of transactions from Alior Bank. It is an element of a permanent system carrier offered by the Bank. After successful integration with the Bank's infrastructure, the service is maintained by Nextrope in the subscription model.

All the document updates are available for the public and bank customers in a public ledger based on the Ethereum network. The solution serves as a Durable Medium.

Technology choice:

Node.js with Loopback framework for serving REST API

Ethereum node

PostgreSQL database

Nginx application server

VPN + Firewall

Key takeaways about Nextrope

Nextrope is a long-term partner for Alior Bank that proves our ability to meet both the highest technological and formal requirements set by large financial institutions within the Blockchain technology area.

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Scope of the project







Next Enterprises has provided the bank with a technology service related to the bank’s implementation of a project using blockchain technologies. As part of the cooperation, the company made the service available in the SaaS model, maintaining a solution on its servers, ensuring its availability for the Bank and guaranteeing the quality consistent with the quality standards contained in the contract.

Tomasz Sienicki

Tomasz Sienicki

Blockchain Strategy Manager at Alior Bank

Working together with the team over at Nextrope defines a whole new level of quality, innovative solutions, and professional services. If you need any support with blockchain technology, you came to the professionals. Would definitely recommend!

Kajetan Komar-Komarowski

Kajetan Komar-Komarowski

Co-owner and lawyer at Lex Secure

November 2017 we have published a game using smart contracts as a distribution and transaction mechanism. Nextrope team supported us in the most important part of the project - creating and testing secure blockchain smart contracts on Ethereum network. I can highly recommend Mateusz and his team, as the true experts in the blockchain field.

Maciej Skrzypczak

Maciej Skrzypczak

CEO Gameset