6 Appendix 2: Device Certificate Information

The Device Certificate is a 1024 byte Microchip-signed X-509 certificate programmed during manufacturing. The certificate is used to guarantee the authenticity of a device and its characteristics.

The following table lists the main fields of the device certificate.

Table 6-1. Device Certificate Fields (1024 bytes)
Offset (Byte)Length (Bytes)Data
4854Signed region of certificate
234120Device Public Key
36816DSN

The device certificate is encoded in the ASN.1 format. To view the content, the certificate must be decoded to a user readable format using the online JAVA tool: http://lapo.it/asn1js/#.

For decoding a certificate, perform the following steps:

  1. Right click PuTTy, select Copy All to Clipboard, and paste the same to notepad, see the following figure.
    Figure 6-1. Copy Device Certificate
  2. Copy the 1024 bytes of device certificate from notepad to ASN.1 decoder, see the following figure and click decode button.
    Important: The sample device certificate (1024 bytes) is provided at:
 For Evaluation kit mpf_an4663_v2024p1_df\Device_Certificate\sample.txt

    Figure 6-2. Certificate Decoding Using Java Script
  3. The web page displays all the fields in certificate, see the following figure.
    Figure 6-3. Decoded Certificate