Cryptographic services library
  1. 1 Database: data at rest protection
  2. 2 Infrastructure: secure transport and authentication
  3. 3 Front-end: store and safely transmit

Themis is a cryptographic services library.

Themis provides cryptosystems for securing data at rest (storage security) and data in motion (asymmetric messaging and session security) via convenient interfaces, available across many platforms.

Crafted with your platform in mind


iOS and Android ready


Wrappers for serverside languages


Growing number of ways to use

Themis provides

Secure Comparator enables ZKP authentication for users and processes.
Storage Cell
Strong data-at-rest protection model powered with many features.
Secure Message
General purpose asymmetric encryption for non-sequential messaging.
Secure Session
Special-purpose asymmetric cryptosystem for session-based transport protection.

Themis Server

Themis Server is a test playground for using Themis: interactive counterpart in communication, and data-driven debug tool for non- networked apps.

Demo apps


0fc enables you to run a secure in-browser group chats with isolated chatrooms, special security features like anonymity, user invite scheme, zero trust to server, yet working history, strong key rotation. 0fc is written in Python and WebThemis.


Sesto is open source general purpose secrets manager for Web with strong security model, featuring multiple layers of cryptographic protection. Sesto is written in Python and WebThemis

Mobile websocket example

MWE is fork of famous Mobile Websocket Chat example, where traffic is protected by Themis. It features iOS and Android clients and Ruby server. This blog post illustrates the integration process.

Copyright © 2014-2017 Cossack Labs Limited
Cossack Labs is a privately-held British company with a team of data security experts based in Kyiv, Ukraine.