Scalable video compression is the encoding of a single video stream in multiple layers, each layer with its own bit rate. Because of the computational complexity of full video encryption, partial encryption has emerged as a general trend for both standard and scalable video codecs. Depending on the application, a particular layer of the video stream is chosen for encryption. In some applications, however, more than one video layer may need to be protected. This results in a more complicated key management as multiple keys are needed. In this paper, we present an integrated approach to encrypting multiple layers. Our proposal is a prepositioned shared secret scheme that enables the reconstruction of different keys by communicating different activating shares for the same prepositioned information. It presents certain advantages over three other key management schemes.