Protection for large (up to 5GB) files

Good day,
I need to protect large (1-5GB) video files (already in ASD). I am using Taifun zip extension with password for files up to 300-400MB, but for bigger files it becomes too slow.
For example I was thinking of an extension with 4 functions:

  1. reading the first f.e 50 bytes from the file header
  2. simple "encryption" of 50 bytes (without altering the number of bytes)
  3. writing 50 bytes to file (replacing first 50 bytes in file header)
  4. decryption of 50 bytes..

Perhaps there is already another solution or I will be happy to sponsor such an extension.
Thank you

Would you only require to change the first 50 bytes of the file?
It looks possible, what way would you need to change it?

Files can be divided into chunks and then converted to string and saved in txt file.
Would that work?

I'm afraid that the complete rewriting of 5GB files will be too slow. I was thinking about reading and writing only of the file header

I need to encrypt those 50 bytes and then write it back without necessity to rewrite the whole ma file

Got it.
It is quite easy to do.

Yeah that seems possible

Thank you Sunny.
Maybe you could implement those:

  • READFileHeader
  • WRITEFileHeader
  • SimpleENCRYPT
  • SimpleDECRYPT
    functions in SAF?
    P.s. I was sponsoring already your SAF improvements and those experiences for me were perfect.

Sure :smiley:

Actually no, it'll make SAF extension more complex. Since you'll be working with ASD so it can be kept in a separate extension.

1 Like

Yes. You are right. The separate extension will be also perfect. Thank you. Alex