A hybrid method for data compression and encryption based on bit packing, 128-based numerals, and bitmap manipulations: application to seismic data

Numerous seismic datasets are routinely acquired, stored and transferred via different systems and networks. Significant reduction of data sizes with encryption would significantly reduce storage media and transmission costs and security. This study presents a novel approach for compressing and encrypting numerical data in descriptive bitmap images. The method depends on the Steim method for bit-packing and the 128-bit numerical system for encryption and bitmap manipulations for compression. The method produced encrypted data capsules in a WebP image file. For seismic data, it is found that the size of the WebP image comprises ~20% of the corresponding binary size with a bit-rate of ~5.6 b/s which is smaller than that of the Steim form, 27% and 8.9 b/s, respectively. The size of the redundant data is reduced to ~0.1% with a bit rate ~ 0.04 b/s. Regarding the compression speed, it is found that the code compresses data with a rate of ~11,118 samples/s or ~ 44 Kbytes/s in average. For the first time, this study provides an unconventional use of an image file to hold a big amount of 128-bit encrypted data in a compressible form. It is proven that the data in the WebP format, regardless of being encrypted, occupies the least amount of storage space among other image formats, that can be easily handled, stored, and shared through clouds and devices safely with a lower cost.