I think dongles (and non-copyable floppies) have been around since the early 80s at least...maybe the 70s. Tamper-resistant CPU modules have been around since the ATM network, I believe, in the form of PIN processors stored inside safes) The fundamental difference between a "dongle" and a full "trusted module" containing the critical application code is that with a dongle, you can just patch the application to skip over the checks (although they can be repeated, and relatively arcane). If the whole application, or at least the non-cloneable parts of the application, exist in a sealed module, the rest of the application can't be patched to just skip over this code. Another option for this is a client server or oracle model where the really sensitive pieces (say, a magic algorithm for finding oil from GIS data, or a good natural language processor) are stored on vendor-controlled hardware centrally located, with only the UI executing on the end user's machine. What I'd really like is a design which accomplishes the "good" parts of TCPA, ensuring that when code claims to be executing in a certain form, it really is, and providing a way to guarantee this remotely -- without making it easy to implement restrictions on content copying. It would be nice to have the good parts of TCPA, and given the resistance to DRM, if security and TCPA have their fates bound, they'll probably both die an extended and painful death. I suppose the real difference between a crypto-specific module and a general purpose module is how much of the UI is within the trusted platform envelope. If the module is only used for handling cryptographic keys, as an addition to an insecure general purpose CPU, with no user I/O, it seems unlikely to be useful for DRM. If the entire machine is inside the envelope, it seems obviously useful for DRM, and DRM would likely be the dominant application. If only a limited user IO is included in the envelope, sufficient for user authentication and keying, and to allow the user to load initially-trusted code onto the general purpose CPU, but where the user can fully use whatever general purpose code on the general purpose CPU, even uncertified code, with the certified module, it's not really useful for DRM, but still useful for the non-DRM security applications which are the alleged purpose behind TCPA. (given that text piracy doesn't seem to be a serious commercial concern, simply keeping video and audio playback and network communications outside the TCPA envelope entirely is good enough, in practice...this way, both authentication and keying can be done in text mode, and document distribution control, privacy of records, etc. can be accomplished, provided there is ALSO the ability to do arbitrary text processing and computing outside the trusted envelope, .) If it's the user's own data being protected, you don't need to worry about the user intentionally circumventing the protections. Any design which removes control from the 'superuser' of the machine is fundamentally about protecting someone other than the user. This, I think, is the difference between TCPA and smartcards. Notice which one has in its short lifetime attracted far more enmity :) Quoting lynn.wheeler@firstdata.com <lynn.wheeler@firstdata.com>:

I remember looking at possibility at adding tamper resisistent hardware chip to PCs back in 83 or 84 time frame (aka the TCPA idea for PCs is going on at least 20 years old now). It was the first time I ran into embedding chip in a metal case that would create electrical discharge frying the chip if the container was breached.

Remember when applications came with their own copy-protection floppy disks? .... it was possible to build up a library of such disks .... requiring all sorts of remove, search, insert ... when switching from one application to another. They eventually disappeared ... but imagine if they had survived into the multitasking era .... when it would have been necessary to have multiple different copy protection floppy disks crammed into the same drive at the same time. The chip was suppose to provide an analog to the CPU serial number used for licensing software on mainframes .... dating at least from the original IBM 370s (store cpuid hardware instruction).

Some of the higher-end applications still do that with some form of dongle (originally in the serial port) that comes with the application .... it doesn't quite have the downside of trying to cram multiple floppies into the same drive concurrently; the serial port dongles allow for them to be inline cascaded ... and in theory still be able to use the serial port for other use at the same time.

i believe that there is some statistic some place about the UK and the US are really great .... that in those two countries the copyright piracy is estimated to only be 50 percent.

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