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In the terms I’ve described, there are many attributes that might be associated with any packet of data sent across the network. For example, the packet might come from an e-mail written by Al Gore. That means the e-mail is written by a former vice president of the United States, by a man knowledgeable about global warming, by a man over the age of 50, by a tall man, by an American citizen, by a former member of the United States Senate, and so on. Imagine also that the e-mail was written while Al Gore was in Germany,
and that it is about negotiations for climate control. The identity of that packet of information might be said to include all these attributes. But the e-mail itself authenticates none of these facts. The e-mail may say it’s from Al Gore, but the TCP/IP protocol alone gives us no way to be sure. It may have been written while Gore was in Germany, but he could have sent it through a server in Washington. And of course, while the system eventually will figure out that the packet is part of an e-mail, the information traveling
across TCP/IP itself does not contain anything that would indicate what the content was. The protocol thus doesn’t authenticate who sent the packet, where they sent it from, and what the packet is. All it purports to assert is an IP address to which the packet is to be sent, and an IP address from which the packet comes. From the perspective of the network, this other information is unnecessary surplus. Like a daydreaming postal worker, the network simply moves the data and leaves its interpretation to the applications at either end.

This minimalism in the Internet’s design was not an accident. It reflects a decision about how best to design a network to perform a wide range over very different functions. Rather than build into this network a complex set of functionality thought to be needed by every single application, this network philosophy pushes complexity to the edge of the network—to the applications that run on the network, rather than the network’s core. The core is kept as simple as possible. Thus if authentication about who is using the network is necessary, that functionality should be performed by an application connected to the network, not by the network itself. Or if content needs to be encrypted, that functionality should be performed by an application connected to the network, not by the network itself.


End-to-End Principle

This design principle was named by network architects Jerome Saltzer, David Clark, and David Reed as the end-to-end principle. It has been a core principle of the Internet’s architecture, and, in my view, one of the most important reasons that the Internet produced the innovation and growth that it has enjoyed. But its consequences for purposes of identification and authentication make both extremely difficult with the basic protocols of the Internet alone. It is as if you were in a carnival funhouse with the lights dimmed to darkness and voices coming from around you, but from people you do no know not know and from places you cannot identify. The system knows that there are entities out there interacting with it, but it knows nothing about who those entities are. While in real space—and here is the important point—anonymity has to be created, in cyberspace anonymity is the given.

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Consider first the traceability resulting from the basic protocols of the Internet—TCP/IP. Whenever you make a request to view a page on the Web, the web server needs to know where to sent the packets of data that will appear as a web page in your browser. Your computer thus tells the web server where you are—in IP space at least—by revealing an IP address. As I’ve already described, the IP address itself doesn’t reveal anything about who you are, or where in physical space you come from. But it does enable a certain kind of trace.

If (1) you have gotten access to the web through an Internet Service Provider (ISP) that assigns you an IP address while you’re on the Internet and

(2) that ISP keeps the logs of that assignment, then it’s perfectly possible to trace your surfing back to you.

How? Well, imagine you’re angry at your boss. You think she’s a blowhard who is driving the company into bankruptcy. After months of frustration, you decide to go public. Not “public” as in a press conference, but public as in a posting to an online forum within which your company is being discussed. You know you’d get in lots of trouble if your criticism were tied back to you. So you take steps to be  "anonymous” on the forum. Maybe you create an account in the forum under a fictitious name, and that fictitious name makes you feel safe. Your boss may see the nasty post, but even if she succeeds in getting the forum host to reveal what you said when you signed up, all that stuff was bogus. Your secret, you believe, is safe. Wrong. In addition to the identification that your username might, or might not, provide, if the forum is on the web, then it knows the IP address from which you made your post. With that IP address, and the time you made your post, using “a reverse DNS look-up,” it is simple to identify the Internet Service Provider that gave you access to the Internet. And increasingly, it is relatively simple for the Internet Service Provider to check its records to reveal which account was using that IP address at that specified time. Thus, the ISP could (if required) say that it was your account that was using the IP address that posted the nasty message about your boss. Try as you will to deny it (“Hey, on the Internet, no one knows you’re a dog!”), I’d advise you to give up quickly. They’ve got you. You’ve been trapped by the Net. Dog or no, you’re definitely in the doghouse.

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