What is the background of the application endorsed by Vitalik? Is privacy communication the next trend?

Deng Tong, Golden Finance

On November 27, 2025, Vitalik posted on X, supporting two decentralized messaging applications, Session and SimpleX Chat, and donated 128 ETH to each of them.

Vitalik pointed out: The digital privacy protection of encrypted messaging is crucial. The next two important development directions in this field are: (i) creating accounts without permission; (ii) protecting metadata privacy.

Both of these software applications are not perfect; they still have a long way to go to truly achieve the best user experience and security. Strong metadata privacy protection requires decentralization, which is inherently difficult to achieve. Users' expectations for multi-device support only add to the challenges. Defending against witch attacks/denial of service attacks in messaging routing networks and on the user end (without the mandatory reliance on phone numbers) also increases the difficulty. These issues need more attention from people. Wishing all teams dedicated to addressing these important issues the best of luck.

1. What are Session and SimpleX Chat?

1. Session

The development of Session began in 2018, initiated by the Oxen Privacy Tech Foundation based in Australia. The project was originally a fork of another instant messaging software, Signal, with the aim of expanding upon its foundation. However, due to concerns over the centralized structure of the Signal protocol and potential metadata collection issues, the team decided to take a different route and created their own protocol, the “Session Protocol.” This approach prioritizes enhancing anonymity and decentralization. During the development process, the team faced various challenges, leading to the necessity of abandoning or modifying many features. In 2024, in response to Australia’s increasingly stringent privacy and surveillance legislation, the Session Technology Foundation was established in Switzerland to take over the development and release of the application.

Session is a decentralized “end-to-end encrypted instant messaging tool” designed to “minimize metadata leakage”—metadata refers to information surrounding the content, such as IP addresses or sending times. Session allows users to create accounts without a phone number or email address. It uses a randomly generated 66-character alphanumeric string for user identification. Communication between users, including messages, voice snippets, photos, and files, is end-to-end encrypted using the Session protocol. Session utilizes the Loki blockchain network for transmission. In 2021, an independent review by the third-party organization Quarkslab confirmed these claims. In 2025, Session announced that it had migrated to its own network, Session Network—a decentralized open-source blockchain network designed specifically for the transmission of encrypted data for the Session instant messaging software.

Session has also issued the token SESH. According to CoinGecko data, the token peaked at nearly $0.3, influenced by Vitalik X's tweet, and has since fallen back to $0.1961 as of the time of writing.

2 SimpleX Chat

SimpleX Chat is also an open-source instant messaging tool, featuring “No user identifiers (user ID)” — no phone numbers, no email addresses, and no random usernames/IDs. It supports end-to-end encryption (E2EE) and the protocol design takes into account resistance to future quantum computing.

According to the white paper on the SimpleX Chat official website: The SimpleX Messaging Protocol (SMP) is a protocol for one-way message sending that relies on intermediate servers. Messages are transmitted through a one-way queue created by the recipient. The SMP protocol allows messages to be sent via SMP servers acting as proxies, using “private routing” to protect the sender's transmission information (IP address and session) from being snooped by servers chosen (and potentially controlled) by the recipient.

SMP runs on top of a transport protocol that provides integrity, server authentication, confidentiality, and transport channel binding. SimpleX servers are among them. The SimpleX network refers to a collection of SimpleX servers that support SMP. The SimpleX client library communicates with SimpleX servers via SMP and provides a lower-level API that is typically not available for applications. SimpleX Agents interact with SimpleX Clients, offering a higher-level API for application use. They are typically embedded in the form of libraries but can also be abstracted into local services. SimpleX agents communicate with other agents through end-to-end encrypted envelopes provided by the SMP protocol—the syntax and semantics of the messages exchanged between agents are defined by the SMP agent protocol.

Next year, SimpleX will launch “vouchers” that users need to purchase and donate to the community (such as the Bitcoin community) to host the required servers.

2. Behind Vitalik's Call: Protecting the Privacy of Instant Messaging is Becoming a Necessity

Under the influence of measures such as the “chat control” proposed by the EU, the privacy issues of instant messaging applications have been a hot topic of discussion. This measure will require platforms like Telegram, WhatsApp, and Signal to allow authorities to review messages before they are encrypted and sent.

The reason why Session and SimpleX Chat have gained Vitalik's favor lies in their precise alignment with the two core directions he proposed: “permissionless account creation” and “metadata privacy protection.” Permissionless account creation means that users do not need to provide any personal identity credentials, completely breaking the identity-binding shackles of traditional communication tools and avoiding the chain risks brought about by identity information leakage; metadata privacy protection goes beyond mere content encryption, extending the protection scope to metadata aspects such as message sending time, sender's IP address, receiver's address, and message size—this information may seem insignificant, but through big data analysis, it can outline users' social relationships, behavioral habits, and even asset status, making its privacy value no less than that of the communication content itself.

Back in April of this year, Vitalik proposed a roadmap aimed at making it easier and more natural for ordinary users to conduct private transactions and anonymous on-chain interactions without requiring major changes to the core protocol of the network. The proposed roadmap covers four main forms of privacy: privacy for on-chain payments, partial anonymization of on-chain activities within applications, privacy for on-chain reads, and network-level anonymization.

Subsequently, Ethereum has been increasingly focusing on “privacy”: during the Ethereum developer conference from November 17 to 22, Vitalik released the Ethereum privacy protection encryption tool Kohaku—a new privacy and security toolkit for wallets provided by Ethereum.

On November 25, as Wall Street banks like JPMorgan, Citigroup, and Morgan Stanley were still grappling with the aftermath of a massive data breach, Vitalik delivered a crucial message: “Privacy is not a feature, privacy is a basic hygiene.”

Alexander Linton, Chairman of the Session Technology Foundation, pointed out: “Unfortunately, the current development of regulation and technology is threatening the future of private instant messaging. However, the challenges faced by private instant messaging are solvable, and I believe Vitalik is very clear about the importance of decentralization in this struggle. Due to regulatory measures such as chat control, everyone engaged in private communication work currently faces some kind of threat, but this support helps us focus on our mission.”

Session co-founder Chris McCabe pointed out: “What's astonishing is that we clearly see that Vitalik and many people around the world understand what true privacy is and what people need to live freely.” Raising global awareness of crypto and decentralized messaging should be an important next step. “If we're going to convey a message to the world, it's that you don't have to be a commodity; you can be whoever you want to be and express yourself freely. Privacy is a right, and you just need to know it exists.”

Zac Williamson, co-founder of the Ethereum Layer 2 network Aztec Network focused on privacy protection, pointed out: “People's lives are increasingly reliant on the digital space. These spaces are easily subject to surveillance that is unparalleled in the real world. Privacy is crucial; it allows people to act freely in online interactions rather than being reduced to digital commodities, with their data collected, sold to the highest bidder, and used to harm users' interests.”

3. Conclusion: Is the next trend the “Privacy” track?

For ordinary users, Session and SimpleX Chat provide a brand new option for private communication, especially in protecting sensitive information, and their future value has begun to emerge; for the crypto industry, the two “explorers” offer more ideas for the comprehensive development of Web3 privacy infrastructure.

Although the current privacy communication track is far from having the grand narrative like AI and DeFi, the attention from Vitalik and the Ethereum team may attract more projects and capital into this field. With increasing global regulations and constant data breach scandals, decentralized privacy communication may very well be the next industry trend as more developers enter the space.