Can anybody help me with decryting zigbee messages?

Hi there.
We use the Perytons Analyzer here - (you need to capture data using one of their supported front-ends…).
They support ZigBee including all their profiles as well as other protocols (like RF4CE, 6LoWPAN, etc.) including deciphering of the different encryption levels.
Based on their blog they even have some initial support for DigiMesh.

Good Luck,

Thanks a lot, but my problem is I do not understand the decrypted data because I could not find any document that describes those hex data resemble what. Do You have any suggestion?

If the packets follow any of the standard ZigBee profiles then the Perytons sniffer decipher them and shows you the different fields of the different layers in the message. Note that, as far as I know, depending on the ZigBee profile you use there are several levels and types of encryption - i.e. Network, Link, etc. - and even such that use a specific link key to decipher a session between two specific devices in a network.
Hope this helps.

If you are using Digi XBee modules, Digi has predefined API packets which are sent by these modules. You can find the description in the product manuals at Digi website.
Depending on the API frame sent by the module, you can easily decrypt the frames using the predefined API frame format provided by Digi.