1. Abstract

Over the last couple of years, instant messengers have grown in popularity and become the primary communication and content distribution media for a huge number of people. They have become a staple and convenient solution for personal and work-related communication. even for building communities, staying on top of the news and consuming entertaining content. People use messengers to stay on top of the news and consume entertaining content, whereas brands and individual creators rely on them to build communities and grow their influence.

However, the consequences of such popularity are issues with both client freedom and security. Most of today’s popular messengers are prone to security and anonymity issues due to their centralized nature. In addition, they require users to disclose their phone numbers and contact books, because apps need them for client identification.

Improving a product's security often entails compromising its usability. However, we believe it's possible to ensure data privacy and communication security without giving up the convenience of current messaging solutions. More so, we want to bring communication to a whole new level and prove it can be both secure and entertaining. We also believe in using blockchain's computing resource monetization opportunities and its transaction validation mechanisms to enable both service node holders and clients to earn tokens or enjoy paid blockchain-based features.

This paper presents Tingl, an open-source secure messaging and content distribution application that uses a distributed network of servers and an onion routing protocol to send end-to-end encrypted messages with minimal exposure of client metadata.

2. Introduction

The use of instant messengers will continue to grow. The global number of mobile phone messaging app users is predicted to reach about 4 bln in 2025.

The reasons for such immense popularity of instant messaging apps are manifold, such as:

• Convenience: Messaging apps allow clients to communicate with others quickly and easily, without the need to make a phone call or send an email.
• Accessibility: Many messaging apps can be used on multiple devices and platforms, making it effortless for clients to stay connected no matter where they are.
• Features: Many messaging apps offer additional features such as voice and video calls, file sharing, and group chats, making them a one-stop-shop for all communication needs.
• Affordability: Most messaging apps are free or low-cost, which makes them accessible to a wider range of people.
• Global reach: With the ability to message anyone in the world with an internet connection, messaging apps have opened up new opportunities for global communication and collaboration.

With such popularity, security, anonymity and censorship concerns grow. The most current methods of protecting client data are focused on message encryption. While such methods work fine for protecting message content, they leave out metadata security completely.

Security concerns include:

• Data privacy: Many apps collect and store large amounts of personal data, which can be vulnerable to breaches and unauthorized access.
• Encryption: Some apps use encryption to protect client data, while others do not, making it important for clients to understand the security measures in place.
• Fake profiles: Messaging apps can be a target for fake profiles and bots, which can spread false information, scam clients, and compromise their privacy.
• Malware: Malware can infect a device through an app, leading to data theft and other security risks.