A new tool based on PURB-like techniques

[covert-encryption]

Hi,

I wanted to inform you that we are getting a lot of feedback on PURBs and Padme, which are extremely popular among the cryptography community. We have independently developed a format (in development since 2019) where we ended up with very similar solutions that your paper proposes, although the paper was not known to us at that point. Having independently came to pretty much the same conclusions suggests that the methods are quite ideal.

However, for padding we created a completely different scheme, as we believe that it is impossible to provide any meaningful security and keeping low overhead using a deterministic padding scheme. This is documented and compared with Padme on our format specification because several people have already told us to use Padme instead.

Message data is shown in grey, and the padding added on top of it in orange. Covert padding is randomized, visualised by fading shades of orange.

Having only very specific sizes of output files can be revealing, so we prefer to allow any byte length and to keep the size distribution flat.

Anyone interested in continuing development on this field while offering practical encryption with the intent of replacing PGP and other similar file/message encryption tools with a smaller and more secure general purpose PURB-like scheme should see our project at https://github.com/covert-encryption/covert