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Vale (Verified Assembly Language for Everest)

Vale is a tool for constructing formally verified high-performance assembly language code, with an emphasis on cryptographic code. It uses existing verification frameworks, such as Dafny and F*, for formal verification. It supports multiple architectures, such as x86, x64, and ARM, and multiple platforms, such as Windows, Mac, and Linux. Additional architectures and platforms can be supported with no changes to the Vale tool.

Vale is part of the Everest project, which aims to build and deploy a verified HTTPS stack.


See the INSTALL file for installing Vale and its dependencies.

Code Organization

See the CODE file for more details on the various files in the repository.


See the Vale documentation for a description of the Vale language and Vale tool.

You can also see our academic papers describing Vale:

Projects using Vale

For cryptography implementations verified with Vale/F*, see HACL*.
For cryptography implementations verified with Vale/Dafny, see the Dafny legacy branch.
For the Komodo secure enclave reference monitor, see here and here.


Vale is licensed under the Apache license in the LICENSE file.

Version History

  • v0.1: Initial code release, containing code written by: Andrew Baumann, Barry Bond, Andrew Ferraiuolo, Chris Hawblitzel, Jon Howell, Manos Kapritsos, K. Rustan M. Leino, Jacob R. Lorch, Bryan Parno, Ashay Rane, Srinath Setty, and Laure Thompson.