Sir,
I have a good experience with networks security and cryptography.
I can give it a try if provided with the file to decipher.
Or I can suggest some solution based on a detailed description you provide.
Either way I should be very useful if not having the optimal solution.
You can contact me & check my profile for previous reviews.
My best regards.
Dear Sir.
I have read your description in carefully .
I think your task means key of AES CFB Module.
I have some experiences in this field.
Please contact me.
Best regards.