"Proprietary" crypto of Skype

At the message of VOIPsa mailing list, Robert Moskowitz said:

"Some time ago, on the user forum I and another pushed for information on the skype crypto and beyond 'AES 256', we were told that information is proprietary.

Sorry, I cannot accept proprietary cyrpto. I can understand 'patent pending' or such. But not silence. "

I agree. If Skype insist on its "proprietary" crypto, those enterprises and professional users, i am afraid, will hesitate to adopt it as their primary communication tools.