hard cryptographic primitives the goal of the attacker is to recover the multicast video stream at the highest possible quality network coding and security can be accomplished via random linear network coding rlnc rlnc is a completely distributed scheme to implement network coding protocols whereby nodes draw several coefficients at random and use them to form linear combinations of incoming packets the resulting packet is sent along with the global encoding vector which records the cumulative effect of the linear transformations suffered by the original packet while on its path from the source to the destination the global encoding vector enables the receivers to decode by means of gaussian elimination next described are concepts techniques and systems related to secure network coding for video streaming referring now to fig4 the operations at a source node e g source node s in fig1 and 2 are illustrated in fig4 in general overview with reference to the exemplary embodiment illustrated in fig4 a source node generates a 3 u00d7 3 lower triangular matrix in which each non zero element is chosen uniformly at random out of all non zero elements of a finite field the plaintext is divided into vectors of 3 elements and the first position of each vector is encrypted using a stream cypher the matrix is multiplied by each of the vectors to generate the payload the coefficients of matrix a are locked using one different key for each line of the matrix.