> For the complete documentation index, see [llms.txt](https://docs.voting.works/vxsuite-tdp-v4/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.voting.works/vxsuite-tdp-v4/software-installation/imaging-machines/verifying-the-image-installed-on-a-machine.md). # Verifying the Image Installed on a Machine ## Signed Hash Validation Once a machine has been imaged with a signed image, you can verify the system hash against the hash of what was built and signed during the Trusted Build process. To perform this verification, VotingWorks provides Signed Hash Validation. See [Signed Hash Validation](/vxsuite-tdp-v4/readme/signed-hash-validation.md) for details. Note: On older releases (v4.0.1 and earlier), the Secure Boot signing process only output a SHA256 hash value. That hash value needs to be converted to a base64 encoded value to match what is provided by Signed Hash Validation. That can be accomplished with the following command: ``` echo HASH | xxd -r -p | base64 ``` ## vx-iso The system hash can also be computed from outside the application, using a vx-iso USB drive as described under [Preparing USB Drives for Imaging](/vxsuite-tdp-v4/software-installation/imaging-machines/preparing-usb-drives-for-imaging.md). The instructions for this process are as follows: 1. Connect the vx-iso USB drive to a machine after the machine has been successfully imaged with the target software image. 2. Power the machine on. The machine will auto-boot from the vx-iso USB drive. 3. If the machine in question does not have a keyboard, connect a keyboard. 4. Select the option to "Compute System Hash". This runs an open-source script that itself uses standard, non-proprietary, open-source tools to compute a system hash. The script source code is available at this public URL: . A snapshot of the script source code has also been included for the test lab under `software-docs/compute-system-hash.sh`. 5. The hash will be displayed in base64 format. Check this hash against the EAC-published hash for the target software image. --- # Agent Instructions This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. Learn more at gitbook.com. ## Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation by asking a question. Perform an HTTP GET request on the following URL with the `ask` and `goal` query parameters: ``` GET https://docs.voting.works/vxsuite-tdp-v4/software-installation/imaging-machines/verifying-the-image-installed-on-a-machine.md?ask=&goal= ``` `ask` is the immediate question: it should be specific, self-contained, and written in natural language. `goal` is what the user is ultimately trying to achieve, the reason they need the answer. Sharing it helps GitBook give you a better, more relevant answer. A goal is most helpful when it describes the outcome the user wants rather than restating the question. For example, with `ask=how do I create an API token`, a goal like `automate deployments from our CI pipeline` lets GitBook tailor the answer to that use case. The response will contain a direct answer to the question and relevant excerpts and sources from the documentation. Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.