Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

The IMEI Code: Your phone’s other number

tedium.co

Post reply on HN
Print view View original

161–170 of 174 posts

Re: The IMEI Code: Your phone’s other number

#161

Post by gkhartman »

jfoutz wrote: post #99
tjohns wrote: post #62

Earlier quoted context omitted.

At least in the US, the 911 infrastructure is dated. In older systems, your caller ID is sent using in-band DTMF tones, which are decoded by the dispatch computer. On newer E-911 systems they get some additional digital address data from the telephone network, but the record format wasn't designed with VoIP or cellular in mind. So in those cases, the telephone network sends a virtual number and the dispatch computer…

Huh. That's a think I've had vague notions of, but you've made pretty explicit. Technology under pressure looks a lot like biology.

I've had this thought before while studying biology in college while working on legacy code as an intern. There's definitely a "designed by natural selection" feel to some old legacy systems.

Re: The IMEI Code: Your phone’s other number

#162

Post by medo-bear »

sambazi wrote: post #111
medo-bear wrote: post #61

Earlier quoted context omitted.

> Made phone theft drop to pretty much zero Use a nuke to kill a fly?

i imagine that phone theft is more common in poorer regions

Stupid assumption. Phone theft including being robbed for your phone, was more common in London, Sydney, Melbourne than in any place in Eastern Europe I lived in.

Re: The IMEI Code: Your phone’s other number

#163

Post by sambazi »

medo-bear wrote: post #162
sambazi wrote: post #111

Earlier quoted context omitted.

i imagine that phone theft is more common in poorer regions

Stupid assumption. Phone theft including being robbed for your phone, was more common in London, Sydney, Melbourne than in any place in Eastern Europe I lived in.

i guess you haven't been living in a crowded place in eastern europe then

Re: The IMEI Code: Your phone’s other number

#164

Post by sambazi »

tredre3 wrote: post #148
sambazi wrote: post #110

Earlier quoted context omitted.

and then proceeds to download a blob to be interpreted by the firmware over plain http

The S in SUPL stands for secure, it's ssl encrypted. Whether or not the implementation is good, I don't know, but saying it uses plain http is patently false.

last time i checked, there was a "http://" url in the agps.conf on android - been a few years though

Re: The IMEI Code: Your phone’s other number

#165

Post by lozank »

Very interesting! Super cool to see it can be used against theft. AFAIK some apps misuse it, though. If Snapchat detects a modified phone (root for example) at any point, it might block your IMEI. (As far as the internet is concerned, they're very secretive about it) Which is a horrible decision, since a phone might be re-locked and refurbished, handed down to someone else, etc.

Re: The IMEI Code: Your phone’s other number

#166

Post by loufe »

vegetablepotpie wrote: post #139
eknkc wrote: post #134

If you buy a phone in Turkey, it's IMEI is registered to a gov authority and you can use / transfer it as you wish. If you happen to buy one from another country, it will be locked after 60 days of use and no carrier will connect it after that. You can use your passport to to prove that it was not imported commercially but you brought it with you and register it. For $1000 (yeah). And it is locked to your ID. Can't t…

> Can't buy a gsm module for your arduiono What do you mean by that? Ostensibly I can. https://www.adafruit.com/product/2687 Note: it’s on back order, but in theory I would be able to buy a GSM module for my Arduino.

FYI "ostensibly" means 'seemingly, but not actually'. In this case I think you mean just "seemingly".

Re: The IMEI Code: Your phone’s other number

#167

Post by ale42 »

ztetranz wrote: post #158
ale42 wrote: post #155

Earlier quoted context omitted.

Passive TCP/IP fingerprinting might tell a lot about the device. You could probably easily tell apart an iPad and a router. But if IMEI checking catches 95% of plan cheaters, it's probably not worth implementing more checks (more checks = more cost and infrastructure to maintain, is it cheaper than the lost revenue?). This said, I find it insane that there are such plans. The cost of a connection should be the same w…

I think there's lots of ways they could tell if they really wanted to. One way is simply looking at the traffic. "Why are apps on your Android phone accessing Windows update servers?". I guess a VPN can solve that and the game continues. Something interesting might happen next week. T-Mobile Home Internet is not supposed to be moved from the registered address but until now that has not been enforced. It's quite popu…

> One way is simply looking at the traffic.

That might have legal implications (wiretap laws, they would be basically intercept your communication). But perhaps TCP/IP fingerprinting too, not sure... On the other hand, with providers that were even injecting code in web pages when HTTPS was not ubiquitous... maybe they don't care too much.

Re: The IMEI Code: Your phone’s other number

#168

Post by skyyler »

lmz wrote: post #78
skyyler wrote: post #44

Earlier quoted context omitted.

https://www.heise.de/news/Zoll-BKA-und-Verfassungsschutz-ver... Not sure where you get your information, but these are routinely used by police to covertly track targets.

Just because they are routinely used for such does not mean it is their primary purpose.

You’re kind of splitting hairs there, aren’t ya?

Re: The IMEI Code: Your phone’s other number

#169

Post by lmz »

skyyler wrote: post #168
lmz wrote: post #78

Earlier quoted context omitted.

Just because they are routinely used for such does not mean it is their primary purpose.

You’re kind of splitting hairs there, aren’t ya?

No. The Internet is routinely used for porn but it is not its primary purpose.

Re: The IMEI Code: Your phone’s other number

#170

Post by kbolino »

thaumasiotes wrote: post #103
kbolino wrote: post #87

Earlier quoted context omitted.

Assuming something like VoIP is in use, you reach other devices with their IP addresses, not MAC addresses.

As far as I know MAC addresses are never used to route a message to a particular recipient. They're used so that devices that overhear the message, but aren't the intended recipient, can ignore that message on the honor system. If you have a wired connection, this makes the MAC completely superfluous. The concept is sort of still valid for wireless connections (or of course for "wired" connections where you have mult…

A typical Ethernet switch operates only at layer 2 and so does indeed route frames by MAC. You need a more expensive, typically managed, switch in order for it to use layer 3 addresses instead and, even then, the initial setup usually relies on layer 2 routing to get an IP address before layer 3 routing can take over. As a sibling comment points out, the whole stack would/does need a rethink to work differently than this. IPv6 SLAAC as mentioned before can potentially eliminate the need for layer 2 addresses but a lot of networks are still IPv4-only, dual-stack, or even layer 3-agnostic.

Note that this is only about last-mile/first-hop. Once you scale past a single LAN segment, routing is mostly layer 3 until you get to core Internet infrastructure which uses ASNs and BGP. At the very least, it is probably sufficient to say that routing across a WAN is all about IP, but if you zoom in on parts of that network of networks, the underlying technologies often use other routing mechanisms internally that don't get exposed to the other parts of the WAN.

Post reply on HN