Security barcodes and other barcodes linked to on-line databases have become commonplace due to the increased availability of mobile phones equipped with high-quality cameras. In this article, the authors provide methods for quantifying the entropy of the embedded barcode data, assuming methods other than the standards-specified error-correcting code (ECC) approaches can be adopted. Higher entropy, which reduces the likelihood of a fraudulent agent being able to "guess" correct barcodes, is measured directly using a variety of novel algorithms and applied to large sets of barcodes. The authors data, however, show that removing ECC provides the additional advantage of increasing the entropy. Thus, all other settings (data payload size, printing technology, substrate used, etc.) being equal, eliminating the ECC increases the security of the information content for the barcodes (DataMatrix) tested.
Marie Vans, Steven J. Simske, "Impact of Scrambling on Barcode Entropy" in Journal of Imaging Science and Technology, 2011, pp 50601-1 - 50601-9, https://doi.org/10.2352/J.ImagingSci.Technol.2011.55.5.050601