vtek
vtek
Sorry, I just now saw this. Cape doesn't support IMEI rotation, it supports IMSI rotation (I suspect it's actually more akin to TMSI rotation, but I don't know enough).
When you turn your phone on or connect to a new cell tower (by moving) your phone transmits both its IMSI/TMSI identification (your subscriber account ID) and your IMEI number (a hardware identifier assigned to your handset by the manufacturer). With 2G/3G, all of this happens in plain text. Under 5G, the IMSO/TMSI is encrypted. And, under 4G, it's a hybrid. But, in all cases as part of the handshake between your phone and the cell network (i.e. the tower operator, and the cell network provider/carrier that owns/leases use of the tower) receive your actual, immutable (normally) hardware IMEI serial number. Cape isn't offering IMEI obfuscation to consumers, it isn't on their road map to do so, and they legally may be unable to do so.
Most of us have (or use daily) a single handset. And, this piece of hardware -- with its unique identifier -- follow you everywhere. I don't realistically expect to be able to hide from a targeted tracking effort by the government (in my case, the US), although I do believe I should be able to and that my government legally should not be doing what it is doing. Rather, the cell carriers, themselves, are also bad actors -- and in the US they are actively participating ($) in aiding our government with its unconstitutional abuses of the citizenry. Cape doesn't have it's own cell network. It's using the cell networks of these other bad actors, so the capacity of these carriers to abuse Cape customers has to be considered.
Cape scrambles your account ID, and they promise not to personally identify you to third parties, such as these other cell carriers -- and I want to be clear that this is not nothing. [I, myself, am testing them out with a temporary phone number, right now.] But, most people have 1 daily driver cell phone. This piece of hardware reliably triangulates at the same house location each night (residences being publicly recorded), and this device can be reliably tracked remotely across carriers, and even into foreign countries. This metadata, can, is, and will be widely abused.
Never mind the government, it's not clear to me that the cell carrier or other commercial interests intending to violate my privacy can't/won't be able associate an IMEI with a personal identity, even without Cape's assistance. There are various other data sources that could be used, besides Cape's customer info, but it's also not clear to me that my mutable Cape IMSI (and therefore my immutable IMEI) can't be connected to my phone number (likely via a HLR/HSS database query, leading to my MSISDN, which in turn yields the bad actor my phone number). Once they have my phone number, they have my identity (and even if I scrub my data perfectly, my phone number and identity are to be found in the non-private, Contacts list of everyone I've ever known). A Cape rep has posted here before, perhaps they will weigh in on this particular attack vector, but I expect there are others.
I appreciate the efforts Cape is going to. I'd like to reward their effort with my businesses, if I can. Also, I understand that they face technological limitations beyond their control. But, if those limitations mean that I can, in the end, still be de-anonymized by nongovernmental, commercial bad actors then the incremental value of Cape's efforts over using a regular cell carrier with its own network and the least-worst privacy policy i can find may be insufficient to warrant Cape's price multiple.
Here's hoping for a better future...