Polish Bank Verifies Documents With Ethereum Blockchain Alior Bank, a bank based in Warsaw, Poland, is using the public Ethereum blockchain to authenticate its clients’ documents, according to a report by Forbes on June 17. According to the report, when a client at Alior receives a document, they can now verify its authenticity by following a website link to its spot on the public blockchain. This means that customers can verify that the document in question was in fact issued, in the exact wording provided, when the bank claims.