Joint encryption and compressed sensing in smart grid data transmission

In smart grid, a huge amount of privacy data need to be transmitted securely and efficiently. Compressed sensing can be used to improve the transmission efficiency by exploiting the data sparsity, while this sparsity is usually destroyed by the encryption process, making compressed sensing inapplicable. A possible workaround is to perform compressed sensing first and then encrypt the compressed data. However, this two-step workaround lowers the efficiency. In this paper, we propose a novel data transmission scheme EncryCS. Compressed sensing in EncryCS provides security and simultaneously enhances the transmission efficiency in one step. The prerequisite of compressed sensing is to construct a measurement matrix satisfying the restricted isometry property that ensures the perfect recovery of the signal. To make the matrix secret and feasible, we generate it with a pseudorandom sequence generator. By using this matrix, EncryCS transforms a large amount of plaintext data into a small amount of ciphertext data. EncryCS is proven to possess a high security. Extensive simulations are performed based on the real-world data obtained from the PowerNet project at Stanford University. The results demonstrate that EncryCS can compress data by order of magnitude, and the transmitted data can be almost perfectly recovered.