This paper proposes a novel geometrical invariant watermark scheme based on fast correlation attacks of stream ciphers. The binary bit sequences of watermark as the initial state are fed into the LSFR, and the output m-sequence is embedded into the triangles that are obtained according to the scale-space Harris feature points and Delaunay tessellations. During the detection, the embedded watermark will be extracted based on the fast correlation attacks technique. Owing to its powerful error-correcting capability, the robustness against both geometrical distortion and common signal processing can be readily obtained. Simulation results show that the proposed scheme is highly robust against all kinds of geometrical attacks even including RBA in the StirMark.