# \[RevEng\] Challenge: Ukrainian receipts: the solution

DevFeed: [\[RevEng\] Challenge: Ukrainian receipts: the solution](<https://devfeed.tech/articles/reveng-challenge-ukrainian-receipts-the-solution-20577.md>)

Original publisher: [Read original article](<https://yurichev.com/blog/receipts/>)

Published: 2025-11-19T23:00:00Z

Content type: article

Language: en

Sources: [Dennis Yurichev](<https://devfeed.tech/sources/dennis-yurichev.md>)

Topics: [data](<https://devfeed.tech/topics/data.md>), [Cryptography](<https://devfeed.tech/topics/cryptography.md>)

Tags: [encryption](<https://devfeed.tech/tags/encryption.md>), [infosec](<https://devfeed.tech/tags/infosec.md>)

## AI overview

A reverse-engineering challenge solution explains that Ukrainian receipt strings are Base64-encoded low-entropy data rather than encrypted content. It identifies recurring zero-byte patterns and a possible header structure.

## Source excerpt

[RevEng] Challenge: Ukrainian receipts: the solution