Backup file modify

[Efo74]

Hello, I have written a backup utility using disk2vhd / autoit  and it works fine. The result backup file is a vhd/vhdx file, is there a simple way to modify this file that only my backup file can read ? The backup files are very large and the encryption takes a long time, I thought of a way to change only a few bytes at the beginning of the file, or do you know some other method?

Thank you for the support.

[TheDcoder]

For VHD (specification) you can just backup the first 512 bytes (copy of footer) and 1024 bytes (header) of the file and any sane program would not accept it as a proper VHD

I imagine you could do something similar with VHDX too but I haven't looked into it

[Efo74]

Thanks, I'll try to do what you suggested.

 

[TheDcoder]

@Efo74 I have also found the VHDX specification, it says that the file header starts immediately and is 1024 bytes long (1 MB), so you can backup that to prevent VHDX from working in other programs

[Efo74]

Thanks for your availability, and for the technical documentation of the two formats, now I have to study and try.

[TheDcoder]

My pleasure, good luck!

[Efo74]

 

I have produced some code, every suggestion is welcome

ReadWrite_Binary1Mb.au3