Just who has legitimate interests within a computer? In this note I restrict myself to the personal computer which is owned by the user, for his own private use—the private computer. First and foremost the owner-operator paid for the computer and if his interests are not met, the vendor should eventually be held accountable. Applications should also be able to defend themselves better to serve the user and guard their reputation. It may come to pass someday that it is in the interest of this primary stake holder, the owner, to provide, within his machine, resources and some privacy to other interests—service providers and other desirable guests—who may wish to veil themselves to guard various sorts of secrets and intellectual property.

An architecture should support these additional interests. Perhaps the supplier of this hardware and software foundation is in a position to warrant such protection to these other interests, contingent on the agreement of the owner, of course. These other cases require hardware that resists tampering to some degree together with novel software foundations.

Here are some deals that might warrant the privacy provided by the apartment:

Software Owner
The great unread bulk of software licenses shows that there is some concern for the property rights of the software owners. Licenses do not serve these concerns well and annoy the customer — even the customer with no plan to disassemble the program. Many of the clauses proscribe behavior that could be well prevented by technical means instead of poorly by legal means. Agents of the user could protect the interests of the user upon installation. If the software has an expiration date built in, this would be manifest to the user’s agent and not buried in the unread license and unread code.
Digital Money
Some deployed money schemes (Mondex) count on protection against the operator of the computer that implements the money, for breaking into such code leads to the unlimited ability to mint new money. This application probably requires hardware tamper resistance that is beyond the state of the art.
eBook Copyright Owner
E-books may be nearly as inconvenient to copy from the screen as paper books. This is what has made copyright viable for the last few decades despite the advent of Xerox.
Music Copyright Owner
This is somewhat more problematical as the quality of the outgoing analog signal probably needs to be good enough that piracy is highly feasible, if not purely digital.
Movie Copyright Owner
Again this protection is as good or better than the eBook. If a key to decrypt the movie must be guarded by the local software and hardware, the tamper resistance must be very good.
Interactive Drama Copyright Owner
The protection here is even better. Builders of interactive works have little to fear from captured video output for that can be used only to see the results of someone else playing the game. Indeed the owner of the work may arrange for high quality export of a particular digital interaction as a means of publicity! You have seen the travelogs of others! Now go there yourself!
Business Partner
Perhaps the user is a contractor to organization Q. Q is then a natural stake holder in the user’s computer. Q’s apartment is attached by VPN to Q’s internal network for data and perhaps voice. Q’s security rules apply within that apartment. Documents can arrive at the apartment from Q and be opened there as safely as if the apartment were within Q’s security perimeter. The user may be a contractor to more than once such organization, each with an apartment in his computer.
Games
There may well be an apartment for some multi player game into which the user allows programmed avatars of other players. Some imagine code to define the avatar’s behavior that is provided by a third party. The protection mechanisms for this have been imagined but not yet produced. There are at least two levels of protection here:
Of these categories, software is unique. The others might be considered as a special case of software. Terms and conditions for using software are complex in current practice and such terms could be largely implemented in software with agents for the parties guarding the respective interests.

Each of these owners of intellectual property may have incentive to produce and deliver material if a revenue stream can be projected. This is to the ultimate benefit of the machine user.

Copyright law was a good hack until bits came along. It is indeed unfortunate to lose the benefits of copyright law. Techniques such as I suggest here are not a one-for-one replacement; they are not much like copyrights but are more flexible. New business models are required which impact IP owners, machine and OS vendors and end users. Perhaps distributers are also in the game. These techniques would be based largely on private contracts between IP owners and vendors of the tamper resistant hardware.

The protections described above protect the guest. It is also natural to protect the user against the guest. Indeed the apartment is confined to keep the guest from damaging material outside the apartment and even isolated to keep the guest, who may have a channel home, from reading information outside his apartment. Isolation can also assure that the guest will continue to serve, contingent on an initial agreement by the guest. This means that software can be delivered so that the author cannot have planted a bomb that causes the software to cease at some future date. Here is a general mechanism to provide such assurance.

I am aware that I claim here solutions to technical problems that are not described anywhere that I know of. I intend to describe such solutions or find references to such.

I discuss here the role of confinement in DRM. A positive account of DRM. My early reactions to Palladium.

I recommend: Stuart E. Schechter, Rachel A. Greenstadt, and Michael D. Smith Trusted Computing, Peer-To-Peer Distribution, and the Economics of Pirated Entertainment which explores the coming conflicts.

detritus
Indeed Hollywood sometimes uses “software” as a term referring to their products. The confusion is appropriate.

I am reminded of internal IBM jargon: The “user” is the one who interacts with the machine, while the “customer” is the one who pays for it. Apple strategically confuses the two.