Researchers have developed a novel encryption scheme for vector maps that combines a four-dimensional (4D) hyperchaotic system with the SM4 block cipher algorithm. This method aims to improve security and efficiency in protecting geographic and cartographic data, which are increasingly vulnerable to cyberattacks due to their growing use in critical applications such as navigation, urban planning, and defense systems. The proposal addresses the limitations of traditional encryption methods, which are often unsuitable for the complex and high-volume nature of vector data.

The proposed scheme uses the 4D hyperchaotic system to generate complex random sequences that are employed in the diffusion and permutation phases of encryption, thereby increasing resistance to statistical and brute-force attacks. These chaotic sequences are intrinsically sensitive to initial conditions, making them ideal for generating robust encryption keys. Subsequently, the SM4 algorithm, a symmetric encryption standard widely adopted in China, is integrated to provide an additional layer of security and efficiency in processing the encrypted data. The combination of both elements allows for nonlinear transformation and effective dispersion of information.

Security and performance test results demonstrate that the scheme exhibits high key sensitivity, strong resistance to differential and statistical attacks, and a good ability to conceal the original vector map information. The distribution of encrypted pixels, information entropy, and correlation between adjacent pixels have been evaluated, showing values that exceed standard security thresholds. This advance could have significant implications for the protection of critical infrastructure and data privacy in an increasingly digitized world dependent on geospatial information.