Is a SAM required for DESFire EV3 / Light readers, or can reader authentication be software-only?

[andrei_l]

I have an existing reader based on ST25R3911B transceiver, but with no SAM
(currently using ISO15693 tags, but this reader supports ISO14443A/B options as well)

Could reader authentication be implemented in software (w/o hardware change), or is a SAM required?

Thank you!

[andrei_l]

Hi Kan,

Thank you for the reply!
More broadly speaking, does a DESFire tag rely on proprietary NXP reader hardware (dedicated SAM or integrated functionality in the reader chip) for authentication, or can the authentication be software-based?

Thank you,

-Andrei

[Kan_Li · Accepted solution]

Hi @andrei_l ,

As far as I know, it is possible to do the authentication on DESFire tags just based on software, but this has lower security than with a SAM. Because the Auth Key is saved inside your application code, so any one has the source code may easily know what the key is. You know,  that would lead to some security issue. so we have DESFire demos running without a SAM but for production you better use a SAM.

Hope that makes sense,

Have a great day,
Kan

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[andrei_l]

Thank you very much, Kan!

[Kan_Li]

Hi @andrei_l ,

 ST25R3911B is not a NXP product, please contact ST for further support on this topic, but for easy implementation, I would recommend NFC reader IC from NXP. Please kindly refer to https://www.nxp.com/products/rfid-nfc/nfc-hf/nfc-readers:NFC-READER for more details.

Hope that helps,

Have a great day,
Kan

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