Can someone shed light on how privacy will be affected by IPv6?
From what I've read, the typical case is that the ISP assigns statically a 64 bit prefix to the user, and the remaining bits are assigned from the MAC address of the devices, or a more opaque scheme when IPv6 privacy extensions are enabled. But doesn't this leave the user fully traceable based on the prefix only?
Compared to cookies for example, IP addresses are a serious threat to privacy/anonymity because they are logged everywhere, sometimes exposed (e.g. Wikipedia anonymous edits) and basically constitute a universal ID that can be used to make links between all kinds of network activities (web, BitTorrent, Skype, whatever...)
Exactly, and my point is that currently my ISP assigns IPv4 addresses dynamically, so I'll get a different one every time I turn on my ADSL modem. I think this is quite common, and as a consequence IPv4 addresses are not a reliable way of identifying a home computer. If every home connection is assigned a static IPv6 prefix, that becomes a reliable identifier. Then you can credibly say "This comment on my blog is from the same computer as this Wikipedia edit from last month!", something you currently cannot say for home computers in general (while work computers are much more likely to have static IPv4 addresses and in that case IPv6 doesn't make it worse).
As I understand it, the privacy extensions in IPv6 were designed to solve another, bigger privacy concern that was totally absent from IPv4: if the second part of the IP address is based on the MAC address, then smartphones and laptops can be traced globally, no matter where they connect to the network (home, hotel room, 3G...)
From what I've read, the typical case is that the ISP assigns statically a 64 bit prefix to the user, and the remaining bits are assigned from the MAC address of the devices, or a more opaque scheme when IPv6 privacy extensions are enabled. But doesn't this leave the user fully traceable based on the prefix only?
Compared to cookies for example, IP addresses are a serious threat to privacy/anonymity because they are logged everywhere, sometimes exposed (e.g. Wikipedia anonymous edits) and basically constitute a universal ID that can be used to make links between all kinds of network activities (web, BitTorrent, Skype, whatever...)