Capturing an encrypted file only poses a problem if the encryption has been hacked. There are multiple solutions on the market today that team encryption with different perks that tailor to this sort of thing. DreamStream is one of leaders in this type of out of the box technology. They aren't as big as Cisco or some of the other security companies but they possess the ability to transfer encrypted files that are only visible as white noise, which would help in the solution as well as there encryption possess a time sensitive 2,048 bit key embedded in a military strength encryption. The solutions are there that is not the problem, it is the Corporate mindset of spending the money to change the systems that they currently have. Even though they say they want to they don't.
http://www.dreamstream.info

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