Old router firmware config file not decrypting?

[rahulkmr69]

So I have 2 old jio devices.

• One of them is Firmware Version SRCMTF1_JCOW414_R2.52 which works fine as can be seen in the screenshot. The decrypted file can be read and contains standard lua configs.

• Another one of them is Firmware Version SRCMTF1_JCOW404_R2.15. I'm able to find the decryption key from the script keyguesser.py but the decrypted file looks like gibberish.

Perhaps I needed to use older methods of decryption.... So I used the keys available at https://github.com//discussions/52 to decrypt the backup but no luck.

What can i do about this? Don't have pendrive handy to try the dumping to pendrive method.