# 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/system-overview/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). After booting from the drive, simply select the option to "Compute System Hash". --- # Agent Instructions: Querying This Documentation If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question. Perform an HTTP GET request on the current page URL with the `ask` query parameter: ``` GET https://docs.voting.works/vxsuite-tdp-v4/software-installation/imaging-machines/verifying-the-image-installed-on-a-machine.md?ask= ``` The question should be specific, self-contained, and written in natural language. 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.