The problem is, a lot of people will find this cool and will also not evaluate the threat landscape. In fact, it's even worse. They will assume the threat landscape has already been evaluated. The code is out there, so it must be good. They will then implement this into some "super duper secure" service which should require a far more security for user authentication. It will then take me 15 minutes of pulling my hair out in a security review to explain to whomever implemented it that it offers no security. The team will walk away from our meeting wondering if I was just trolling them and ask how their entire team could have made this mistake. They will then come to the conclusion they are smart and I must be wrong. They'll then call me back to explain again, at which point I'll take them through a full video demonstration with their VP of operations on the call. This time they will actually "get it" because they saw it exploited on video. Their VP of operations will then fire the project manager and lead developer and I'll feel like shit for being responsible for the termination of two careers.
Another example - you can't use uber on a desktop without going to m.uber.com last I checked. There's no way to order trasnportation without that m. (why!)
Another - gmail. You either need another email or a phone, and at the time, neither were possible. (why!!)
For tons of reasons, I just don't like having a phone in my pocket 24/7/365. Mostly, I just enjoy the peace of mind of being unreachable. I've been oncall for years, but that oncall vibe is extending more and more into social situations, for the worse. I hate it. Devs - PLEASE account for those like me! I'm really tired of people telling me (accurately :(.) "You wouldn't have these issues if you had a phone." on account of your laziness or lack of awareness for sensible security.
Note, I'm not a criminal, I just play one in my day job.
: for some level of security. My father was a farmer at that time and I know he wasn't talking about a nation state adversary ;-)
Just for fun i went ahead and verified 2024561414 with the demo of this thing. It gave me a nice little check mark showing that I was definitely the White House
It's used in many places, but mostly offices. An office might have an exchange system, with features like voicemail and routing different types of call over different networks.
I have a personal account which gives cheap international calls, which I added to my android phone. I can receive calls at my SIP address, from anyone on any provider. When I make a call, I'm given the option of using the mobile network directly, or SIP.
Naturally, neither the phone networks not the big tech companies want you to use SIP. They'd rather you used normal calls, or their proprietary system.
And there are various providers which will let you do 'trunking' into the phone system, so you can have any number of handsets with the same origination number appearing on outgoing caller ID.
I would really love to hear a telecom engineer explain why the true origin info isn't accessible to the called person. A telephone call is a two-way connection -- the path in both directions must be known otherwise you won't have a two-way conversation.
A telephone call is not email or an old-fashioned letter. Both of those are one-way communications, so if the intermediaries don't carefully track the email or letter as it progresses through the pipeline, you have spoofed email or untraceable letters.
But at the lowest level of the telephony protocol, the true and correct path to the originating caller has to exist. Otherwise your voice won't travel to the other person. I'm curious to know why that really deep reverse route has never been made available to public (as an API or a purchasable feature or in any other form).
Telephone isn't really like IP routing. If D wants to call P, the connection might get set up like this:
D -> K -> H -> V -> P
See what happens is D sends a message called "Call Request". This creates a channel id (D,C1) between D->K. K will then create it's own "Call Request" with it's own channel id (H,C2) which tells H to bill K for this call. Only K will know both the channels C1 and C2 and will bridge them internally. When H makes a "Call Request" to V, it has it's own billing arrangement with V and they agree to simply count calls, so H doesn't actually forward anything except the channel id (nil,C3). V gets away with this because the wire is clearly marked with "K TELEPHONE INC". Eventually P gets an "Incoming Call" message with it's channel id (P,C4), and can accept the call or reject it. If he accepts it, then each party will send "Accept Call" messages back down the chain.
These channel ids are used to actually carry the phone call (or data packets, or whatever).
"Caller ID" isn't the "source of the message", just some data transmitted along with the ringing sound, and as you can see the circuit doesn't have a globally unique identifier. If someone doesn't transmit who to bill, then nobody will get billed for that call (and maybe nobody will be!) but V doesn't want to send bills for this call all over the country so V only sends bills to a few carriers and its own customers.
All the bills have the "correct calling numbers on them" because of some extra billing data that's included in the call. This billing data might be omitted (the bill says "NUMBER BLOCKED"), and it clearly isn't required to establish the call. People can ask their phone company to ignore calls that have a blocked number.
Phone companies used to trust each other not to spoof this information, and now that calls from certain numbers aren't usually billed differently than from any other numbers, this doesn't cause a problem with billing -- only with people who seek to use "making a call from" an authentication method.
The companies could enforce the side channel info as the actual call origin, but they don't want to. Just like snail-mail spammers they're paying more money than residential customers will pay to require that info.
It's broken because it serves the purposes of the phone companies to keep it that way. This is what you get by detaching profit from ethics.
I'd settle for my phone company dropping calls with spoofed caller ID - like 0, my own number, foreign calls with local numbers, local numbers that don't even terminate, etc..
Indeed I think origin should be legally required even if it's "K phone network" - I don't mind blocking all calls via companies that service spammers.
The current telephone infrastructure wasn't designed. It grew: Verifying a call would involve either tying up an additional channel back (doubling the cost of the infrastructure), or replacing (parts of) the infrastructure with something better designed- like a TTL "ping" packet going backwards to verify the route on the original channel. Getting everyone to change their hardware is hard. Just look at how long it's taking to get IPv6 out.
Fortunately, tracing a call isn't like television: You do not have to "keep him talking". You can ask the phone company to research the calls made to your number at a specific time, and in the process of reconciling billing, the phone company can find out, and then you can use the judicial arm to deal with people who spoof the calling number.
I'm not specifically wanting call verification I'm wanting them to detail origin if they have it (they can use the callerID field to forward that information to me) or to refuse to route calls that are clearly spoofed. If the callerID is 0 then the phone company knows it's spoofed and can block it, but they don't get paid for that - that's the only reason I can come up with for them to forward calls that have certain incorrect origin information. At least when I look at the callerID display and it says my number I know that it's not possible that call is anything other than spam - why would a company choose to forward such calls if not for the money they get for doing so?
>You can ask the phone company to research the calls made to your number at a specific time, and in the process of reconciling billing //
Are you telling me that at the point the company decides to carry a call from an external source they don't know if they're going to be able to bill that company for the call? Surely they know the network origin of the call - they at least know the hard infrastructure it's arrived at their periphery from, they have to right?
So when I get a foreign call centre spammer on the line the company knows at the very least that was forwarded to them from, let's say, France Telcom [made up example] and could give me that info in the callerID field.
The phone company that provides you service simply does not have this information at the time of the call. They only know for certain who to bill. Changing this requires replacing a lot of deployed equipment.
Furthermore, it is already illegal to spoof caller ID in the USA, and the UK and elsewhere.
You can indeed tell your phone company to reject calls without caller ID, and indeed from various switches. If one gets through, you will need to note the time that you received the call and file charges with the authorities.
The phone company will then research the call, and produce for law enforcement who in fact made the call.
> If the callerID is 0 then the phone company knows it's spoofed and can block it, but they don't get paid for that
You are confused: The callerID field (aka "presentation number" in the UK) is in-band and transmitted by the calling station, the billing field is out-of-band and transmitted by the receiving station's "next hop". It is also not normally presented to the callee, although with a special kind of connection you can receive it.
> when I look at the callerID display and it says my number I know that it's not possible
You should contact law enforcement. This is a crime.
> Are you telling me that at the point the company decides to carry a call from an external source they don't know if they're going to be able to bill that company for the call?
Your phone company doesn't bill the caller. They only bill the other phone company that handed them the call.
> Surely they know the network origin of the call
The "network origin of the call" as you put it, is the phone company that handed them the call. It is not the person who dialled the number.
Even if all of the phone companies are really one (limited) company, the individual switching offices don't send this information down with the call for efficiency reasons.
> So when I get a foreign call centre spammer on the line the company knows at the very least that was forwarded to them from, let's say, France Telcom
No. "The company" only knows the company that switched them the call. It takes research to work out who actually made the call that is normally distributed by separate offices because it's more efficient.
The telco has some connection to a customer site which carries signaling data and N concurrent voice channels. A potentially large block of numbers are routed down that link by the telco. When he customer makes an outgoing call it sends whatever it wants (or nothing) as CID.
A national franchise with 1,000 stores serviced by 30 different small town telecoms might all send the national HQ number as caller ID, even though the calls do not jump through the national HQ first.
There is no will among the various telecoms to build and integrate a whitelist system that interoperates, so they leave it wide open.
You can't just find out who a phone number belongs to, and phone numbers do not have to ring to anyone on the other side to be valid outgoing CID numbers. It's unclear how such a whitelist system would help anyone, anyway.
This is by design and used in many cases. Call forwarding, for instance. Or even just the basic case of using multiple providers to route outbound calls. Some might be cheaper than others, so you need to select on a call by call basis. Also, think of international calls. How is Idaho Telco XYZ supposed to be able to verify that this call from Zambia really belongs to ZambiaCom XYZ? And vice versa.
Also note that there's simply no requirement to even having a number. You could just be placing outbound calls (like SkypeOut). Or no one to one mapping: an office sharing one number for outbound calls, or a single telemarketer changing numbers call by call as they dial for different customers.
Call forwarding is fine as long as the spoofed number is also associated with the caller. But anyone that lets people call using a number that's not theirs at all should be booted off.
Now you get all the calls from that provider to that number. Forward them to the actual destination (using an unrelated provider) and no one will notice for a while. Except, you get all the calls and media.
I believe the SMS verification is something that companies use to avoid liability alone, technically they can use any number as the caller ID if they choose to.
I've worked in VOIP quite a bit, and even built a product based on the fact you can fake caller id over SIP i.e. "keep your number but lower your outgoing call rates"
What do you guys think?
I'm getting tired of services that only accept facebook users.
Having a facebook login or any other facebook service requiring the user to be a facebook user is not bad in itself (and can be pretty useful), but it should _always_ have an alternative.
That's why I think projects like Dial2Verify Twilio are a great thing. They're still not perfect though, as some said here on HN.
Just pay the 0.02¢ or whatever phone services charge these days. If your business is actually big enough to have to worry about phone verification, do it right. Users don't like to call your number since they don't know the costs associated with it (especially international users).
Furthermore, it makes number spoofing much harder.
You can get more than 1-bit of information as well if you sync the clock on your phone with the recipient. That gives you approximately 3.3 bits of information if you use the minute modula 10. This only works if you previously agree upon a meaning for values (Mod 0: Yes, Mod 5: No, etc).
The classical text message verification schemes barely have this issue in most of the world as the recipient pays nothing, but of course the sender gets billed instead.
Also, I have to assume Twilio would look at this as a form of abuse.
They can't, that's why there's an ever-increasing amount of verification.
Could we also do phone verification at no cost, however instead by outbound call? Is there any free/paid host providing such service?