Over the last week, it has been become clear that Apple is embedding some identifying information in songs purchased from iTunes, including the name of the customer and his or her e-mail address. This has raised the ire of consumer advocates, including the Electronic Frontier Foundation which addressed this again yesterday.
Last year, I published a paper entitled Mistrust-Based Digital Rights Management (online preprint available here). In that paper, I argued that as we switched from content products such as CDs and DVDs to content services such as iTunes, Google Video and YouTube, we would embrace identity-based digital rights management. This is exactly what we are seeing from iTunes. How should we assess identity-based DRM?
Take a step backwards. As long as I keep my songs to myself and don’t share them, the embedded information shouldn’t matter. The information may facilitate interactions between Apple and its customers and might make it easier to verify whether a particular song was purchased from iTunes, but this doesn’t seem to be the central point of embedding identity in the songs.
Instead, identity matters if I share the song with someone else. Identity travels with the content. If I know that and care, I will be less likely to share the content indiscriminately over p2p networks. Why should I care? It depends on what happens with the embedded information. One use would make it possible for Apple to identify who was sharing content on p2p networks. Having traced content to its purchaser, Apple might choose to drop that person as a customer.
But Apple could do this without embedding the information in the clear. As Fred von Lohmann asked in his post on the EFF blog, why embed identity in the clear rather than as encrypted data? After all, if Apple intends to scour p2p networks, it could do so just as easily looking for encrypted identities.
Apple might have a different strategy, one that relies on third-party sanctions, and that strategy would require actual identities. Suppose Apple posted the following notice on iTunes:
“Songs downloaded from iTunes are not to be shared with strangers. We have embedded your name and email address into the songs. Our best guess is that if you share iTunes songs on p2p networks, your name and email will be harvested from those songs and you will receive an extra 10 spam emails per day from third parties.”
Encrypted information works if Apple is doing all of the detection. It would even work, as I suggested in my paper, if Apple relied on third parties to do the detection by turning in p2p uploaders to Apple. We could run that system with encrypted information. All that is required is that the rat knows that he is turning in someone; he doesn’t need to know who that person is exactly.
But a third-party punishment strategy would probably be implemented using actual identity. The spammer who harvests the email address inflicts the penalty for uploading, not Apple itself. For Apple to drop out of the punishment business, it needs to hand off identity. Obviously, extra spam is just one possible cost for disclosing names and emails; other costs would further reduce the incentive to upload.
Disclosing identity is a clumsy tool. It doesn’t scale very well. It will work most powerfully against the casual uploader. It offers no (marginal) deterrence against someone who would upload lots of songs anyway. My mistrust-based scheme (described in the paper) might work better in those circumstances.
So far, Apple doesn’t seem to be saying much about what it is doing. It needs to be careful. As the Sony BMG fiasco—also discussed in the paper—emphasizes, content owners may not get that many opportunities to establish technological protection schemes. Each one they get wrong makes it that much harder to try another scheme later, given the adverse public relations fallout. As I suggest above, Apple may have a legitimate strategy for disclosing identity in the clear. It will be interesting to see what Apple says next.