A method and a device for distributing patterns to scanning engines for scanning packets in a packet stream are provided. The method includes providing a plurality of scanning engines and patterns, calculating a respective distance metric for every pair of patterns, and providing a plurality of distribution functions. Further, the method includes calculating a respective sum of the calculated distance metrics for distributing the patterns for each of the distribution functions, and utilizing the sums for selecting a distribution function of the D distribution functions for distributing the patterns to the M scanning engines. A device for implementing the method is also provided.