IBM/MS-DOS 6 stored compressed programs by having a decompression stub and the compressed program as the remainder of the file data.
On Sat, Jan 13, 2024 at 1:50 PM Grant Taylor < 0000023065957af1-dmarc-requ...@listserv.ua.edu> wrote: > On 1/13/24 13:39, Gibney, Dave wrote: > > It should be obvious, but as a practical matter, you can't encrypt > > the modules that do the decryption and it also follows that you can't > > encrypt the modules that provide the execution environment (z/OS) > > for these modules. > > I would like to agree with you. > > Viruses (for PCs) have been self-decrypting for a long time. > > Given how people espouse that the mainframe can do everything that a PC > can do ... I think it stands to reason that someone with sufficient > motivation /could/ write a mainframe program that would decrypt itself. > > If we accept that it's hypothetically possible to write a mainframe > program that can decrypt itself, then could we also accept the > hypothetical possibility to do the same with a program that is part of > the OS? > > It's been a very long time since I've looked at low level mainframe OS > IPL / boot strap methods and procedures. But I'm confident that the > first part of the program that IPLs off of DASD doesn't know how to do > most of what the OS ultimately does. > > It's all about have just enough recognizable -> executable code that can > decode / decrypt more recognizable -> executable code that can decrypt > even more. > > Hence in /concept/ I don't agree with you. > > > > -- > Grant. . . . > > ---------------------------------------------------------------------- > For IBM-MAIN subscribe / signoff / archive access instructions, > send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN > -- Mike A Schwab, Springfield IL USA Where do Forest Rangers go to get away from it all? ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to lists...@listserv.ua.edu with the message: INFO IBM-MAIN
