Hello Paul,
Sorry to say, Currently there is no certificate/acknowledgment. we will discuss this with our team.
Here I will explain how AxCrypt secure delete works.
AxCrypt Secure Delete simply open the file using normal file system calls, then overwrite the contents of the file with random data, issue an instruction to the operating system to flush (i.e. actually write the data to disk). This will stop normal file recovery using the recovery tools.
However, there are many caveats depending on the technology used underneath.
If you have Windows “shadow copies” enabled, there may be older copies available. If you have Windows compression enabled, the actual data written is likely not what the program thinks. If the drive is a SSD device with wear levelling (most do) then special software may be able to recover data, although it’ll be hard to re-assemble whole files without a lot of work. There are other special situations too.
As has been evidenced by the actions of various security agencies in the last couple of years, the only apparently trustworthy data-sanitation tool is a power drill, sledge hammer or high pressure compactors.
AxCrypt secure delete will suffice for most reasonable situations. If you want a more secure non-destructive tool complement with periodic use of tools such as Eraser (it will overwrite all empty blocks on the disk until the disk is full). If you think the man is after you, see above suggested power tools.