The emissions tracking proposal might have another sort of relevance to cryptography. Assuming (it's a big assumption, but entertain it for a moment) that we agree that some type of automatic enforcement mechanism for emissions-based repairs were a good thing, how could it be built without identifying any individuals to the authorities? What I find so utterly over-the-top about the ARB proposal is that it is capable of maintaining records on everybody everywhere, whether they are violating any laws or not. Of course they'll promise to protect privacy, and they may even promise not to capture any records for people whose emissions fault codes come up clean (though they say nothing about this in the RFP). But such assurances would be nonsense, since once the system is in place a simple software change would cause the system to revert back to the total-surveillance functionality described in the RFP. The key, then, is designing systems so that simple software changes under the control of the authorities can turn them into instruments of oppression. This design consideration is hard to even formulate accurately in the context of traditional system design methodologies, which assume that everything in sight comes with identifiers and that *the* way for a system to relate to something is to represent it in terms of those identifiers. Digital cash and other such schemes are so profound precisely because they break with this underlying assumption, forcing systems to think thoughts like "this person (whoever s/he may be) has paid $1 to travel on this road", "this person (whoever s/he may be) is eligible for an upgrade to first class", "this person (whoever s/he may be) is obeying emissions laws", and so on. Philosophers and linguists call these "indexical" (or, more precisely, "deictic") because they identify an individual contextually without appealing to a name or other universal identifier. Phil