OSHI vs Session — Anonymous Messengers Compared

OSHI and Session are natural rivals: both are open-source, both reject the phone-number model, and both are designed for people who want to communicate without revealing who they are. If you have already decided you want anonymity, this is the comparison that matters most.

Session takes an onion-routing approach: it forked from Signal, assigns you a random Session ID instead of a phone number, and bounces your messages through a decentralized network of service nodes to obscure metadata — conceptually similar to Tor. OSHI also drops the phone number, but its distinctive strength is working with no internet at all via a Bluetooth and WiFi mesh, alongside Tor routing and a self-hosted blob store. Both have real merits; the right choice depends on whether your priority is metadata-resistant internet routing or true offline resilience.

Feature comparison: OSHI vs Session

Where Session genuinely wins

Session deserves credit as a serious, metadata-focused messenger. Its onion-routing network means no central server ever sees both who you are and who you are talking to, and because it uses a decentralized set of service nodes, there is no single company operating the infrastructure. It requires no phone number, has been through third-party security review, and offers clean cross-platform clients including desktop. For a threat model centred on "hide my metadata from the network while I use the internet," Session is a well-designed, mature option.

The one thing to know about Session's encryption

An honest comparison has to mention a real change: in 2023 Session moved away from Signal's Double Ratchet, removing perfect forward secrecy in favour of its own "Session Protocol." Session argues this suits its store-and-forward, multi-device onion network, and messages remain end-to-end encrypted. But it is a meaningful design decision that some privacy researchers have debated, and it is worth understanding rather than glossing over. OSHI retains a Double-Ratchet-style construction with forward secrecy. Neither approach is simply "wrong" — they optimise for different network models — but you should know the difference.

Where OSHI is different

The clearest divergence is offline capability. Session needs the internet to reach its service-node network; if the internet is down or blocked at the access layer, Session cannot deliver. OSHI can fall back to a device-to-device mesh over Bluetooth and WiFi, relaying through nearby phones with no infrastructure whatsoever — the scenario Session structurally cannot cover. OSHI also adds text steganography to hide that a message exists at all, and on-device AI for translation and writing. Session, conversely, has a more mature and specifically metadata-oriented onion network and a completed public audit, which OSHI does not yet have.

Who each app suits

Choose Session if your priority is metadata-resistant messaging over the internet with a decentralized, audited onion network, and you are comfortable with its post-2023 protocol choices.

Choose OSHI if you want the same no-phone-number anonymity but also need to keep communicating when the internet is unavailable or censored, value forward secrecy, and want extras like steganographic channels and on-device AI. Both are open source, so you can verify either one's behaviour directly.

Frequently asked questions