https://devzone.nordicsemi.com/f/nordic-q-a/100560/psa-initial-attestation-token-signature-verificationHi We have received Initial Attestation report from device using psa_initial_attest_get_token and we want to verify signature. Today we don&#39;t know how signature is calculated inside psa_initial_attest_get_token api, signing key that we set is ofen-USTelligent Community 13Fri, 09 Jun 2023 08:01:46 GMThttps://devzone.nordicsemi.com/thread/430136?ContentTypeID=1Fri, 09 Jun 2023 08:01:46 GMT137ad170-7792-4731-bb38-c0d22fbe4515:2c8df8a3-3ed9-487c-ac91-a1354a700e68Hieu<p>Hi Dilip,</p> <p>There is a tool for validating the Initial Attestation Token, provided by the&nbsp;Trusted Firmware org.</p> <p>You can find its source code it here:&nbsp;<a href="https://git.trustedfirmware.org/TF-M/tf-m-tools.git/tree/iat-verifier?h=release%2F1.8.x">https://git.trustedfirmware.org/TF-M/tf-m-tools.git/tree/iat-verifier?h=release%2F1.8.x</a>.</p> <p>From the source code, you will also be able to investigate the compilation and decompilation of a token.</p> <p>Hieu</p><div style="clear:both;"></div>https://devzone.nordicsemi.com/thread/429927?ContentTypeID=1Thu, 08 Jun 2023 09:17:59 GMT137ad170-7792-4731-bb38-c0d22fbe4515:9a5bc242-5ebc-4f35-baeb-a6cd6803c70ddilip agrawal<p>yes Hieu</p><div style="clear:both;"></div>https://devzone.nordicsemi.com/thread/429923?ContentTypeID=1Thu, 08 Jun 2023 09:10:28 GMT137ad170-7792-4731-bb38-c0d22fbe4515:06b14517-2e62-4326-91a9-71f808720c3aHieu<p>Hi Dilip,</p> <p>If I understand correctly, the reason you want to know how the signature is calculated is to perform a validation, right?</p> <p>I will investigate this and get back to you soon.</p> <p>Regards,</p> <p>Hieu</p><div style="clear:both;"></div>