Abstract
Network coding techniques such as fountain codes are a promising way to disseminate large bulks of data in a multicast manner over an unreliable medium. In this work we investigate how to conceal such encoded data stream on its way to numerous receivers with a minimum investment. Compared to conventional 'encrypt - encode / decode - decrypt' approaches, our solution is preferable for two reasons: i) it causes less CPU investment for encryption and decryption up to orders of magnitude; ii) besides hiding the data, we also hide the coding information from an eavesdropper.