3.3 KiB
Tillitis Key 1
Introduction
Tillitis Key 1 (TK1) is a new kind of USB security token. What makes the TK1unique is that it allows a user to load and run applications on the device, while still providing security. This allow for open ended, flexible usage. Given the right application, the TK1 can support use cases such as SSH login, Ed25519 signing, Root of Trust, FIDO2, TOTP, Passkey and more.
During the load operation, the device measures the application (calculates a cryptographic hash digest over the) before running it on the open hardware security processor. This measurement is similar to TCG DICE.
Each TK1 device contains a Unique Device Secret (UDS), which together with the application measurement, and an optional user-provided seed, is used to derive key material unique to each application. This guarantees that if the integrity of the application loaded onto the device has been tampered with, the correct keys needed for an authentication will not be generated.
The key derivation with user provided seed allows users to build and load their own apps, while ensuring that each app loaded will have its own cryptographic identity, and can also be used for authentication towards different services.
The TK1 platform is based around a 32-bit RISC-V processor and has 128 KB of RAM. The current firmware is designed to load an app that is up to 100 KB in size, and gives it a stack of 28 KB. A smaller app may move itself in memory to get larger continuous memory.
All of the TK1 software, FPGA logic, schematics, and PCB layout are open source, as all security software and hardware should be. This in itself makes it different, as other security tokens utilize closed source hardware for its security-critical operations.
Tillitis Key 1 PCB, first implementation
Documentation
- System Description
- Threat Model
- Framing Protocol
- Boards
- Software
- Firmware
- Toolchain setup
- Quickstart to program the Tillitis Key 1
- Release Notes
Note that development is ongoing. For example, changes might be made to the measuring and derivation of key material, causing the public/private keys of a signer app to change. To avoid unexpected changes, please use a tagged release. Read the Release Notes to keep up to date with changes and new releases.
Applications and host programs that communicate with the apps are kept in this repository: https://github.com/tillitis/tillitis-key1-apps
About this repository
This repository contains hardware, software and utilities written as part of the Tillitis Key 1 project. It is structured as monolithic repository, or "monorepo", where all components live in one repository.
The repository follows the OpenTitan layout.
Licensing
See LICENSES for more information about the projects' licenses.
All contributors must adhere to the Developer Certificate of Origin.