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1. Download the Google Voice app. This phone number works for some but not all 2FA services. Not all, because some explicitly forbid GV numbers because they're

1. Download the Google Voice app. This phone number works for some but not all 2FA services. Not all, because some explicitly forbid GV numbers because they're afraid of fraud. GV can receive SMS messages over wifi. 2. Ask the cell phone company for a femtocell. These used to be called "AT&T Microcells" and they were cheap. I used one before cell service improved because I live in the mountains. But apparently AT&T don't make them any more and now they cost $2500. https://www.waveform.com/products/verizon-network-extender-for-enterprise-3 https://www.waveform.com/products/verizon-network-extender-f... 3. Subscribe to mightytext.net so you can get SMS on your computer. I don't know if this works if your cell phone can't get signal; I use it because I find it easier to use my laptop keyboard to type SMS messages than to use my thumbs on my phone.

lxgr 1y ago
> Subscribe to mightytext.net so you can get SMS on your computer. I don't know if this works if your cell phone can't get signal It can't – how would it? The only entity that can forward texts is the carrier, and I doubt that that service is integrated with all US carriers to somehow get them forwarded (which is technically quite difficult for various legacy protocol reasons). Apple's satellite messaging service is the only solution I know of that can somehow hook into carriers' SMS home router (or IMS equivalent) infrastructure to intercept and out-of-band forward SMS.
- hedora 1y ago
  Sms and signaling system 7 are incredibly insecure. It has to be so it can support scammers that call you from spoofed numbers. Anyway, it’s probably possible to make a service like that. You might need to route through a country with permissive laws.
  - lxgr 1y ago
    SS7 is very insecure, yes, but intercepting inbound SMS is still orders of magnitude more difficult than spoofing sender/caller numbers. Allowing SMS interception without the home network's consent seems like a quick way to get offboarded as a roaming partner.
- miki123211 1y ago
  > Apple's satellite messaging service is the only solution I know of that can somehow hook into carriers' SMS home router Are you sure it actually does this? I thought it was a pseudo-carrier that could speak MAP / Diameter, and just pretended you were roaming with them when you used satellite connectivity, perhaps with the original carrier's knowledge and consent. As far as I understand, that's how this kind of service usually gets implemented.
  - lxgr 1y ago
    I assumed that that's how it works because I couldn't think of any other way to achieve the observed behavior, but pseudo roaming sounds plausible too, and presumably requires much less work on the carriers' side! Would that approach also allow the extra functionality they seem to be offering, such as only recently messaged numbers and emergency contacts being able to send messages to satellite users, though? I suppose they could just reject all MT-Forward-SM with sender numbers they don't like? > As far as I understand, that's how this kind of service usually gets implemented. Do you have any other examples for solutions like this? Are you thinking of (pre-VoWifi) carrier apps or services that could receive texts, sometimes on multiple devices?
    - miki123211 1y ago
      > Do you have any other examples for solutions like this I have a vague recollection that Pebble had something like this to get texts on the Pebble watch. > Would that approach also allow the extra functionality they seem to be offering, such as only recently messaged numbers and emergency contacts being able to send messages to satellite users, though? Hmm, you could definitely do this with a "Stripe-like" approach, where the actual traffic goes over the usual protocols to ease implementation, but the carriers provide Apple an API to query messaging history in some way (which they probably already offer in their apps, and so have good integrations for anyway). Stripe uses this pattern for fraud detection. Their card transactions still go over the antiquated ISO protocols from the 80's, because that's just what everybody integrates with and agrees on, but they can also speak a custom API directly with participating banks, mostly for better fraud detection and fraud-related information sharing.
magicalhippo 1y ago
4. Get a USB modem and hook it up to a computer somewhere safe that has coverage, and access it via internet. I'm building the opposite, using the modem and a Raspberry Pi to send me metrics from my cabin, but could easily work in reverse. While prototyping I had it parse SMS messages I sent it. Obviously not for everyone but we're on HN here...
Loudergood 1y ago
The real bonus to security here, access to your SMS is protected via MFA.

lxgr 1y ago

> Subscribe to mightytext.net so you can get SMS on your computer. I don't know if this works if your cell phone can't get signal It can't – how would it? The only entity that can forward texts is the carrier, and I doubt that that service is integrated with all US carriers to somehow get them forwarded (which is technically quite difficult for various legacy protocol reasons). Apple's satellite messaging service is the only solution I know of that can somehow hook into carriers' SMS home router (or IMS equivalent) infrastructure to intercept and out-of-band forward SMS.

hedora 1y ago
Sms and signaling system 7 are incredibly insecure. It has to be so it can support scammers that call you from spoofed numbers. Anyway, it’s probably possible to make a service like that. You might need to route through a country with permissive laws.
- lxgr 1y ago
  SS7 is very insecure, yes, but intercepting inbound SMS is still orders of magnitude more difficult than spoofing sender/caller numbers. Allowing SMS interception without the home network's consent seems like a quick way to get offboarded as a roaming partner.
miki123211 1y ago
> Apple's satellite messaging service is the only solution I know of that can somehow hook into carriers' SMS home router Are you sure it actually does this? I thought it was a pseudo-carrier that could speak MAP / Diameter, and just pretended you were roaming with them when you used satellite connectivity, perhaps with the original carrier's knowledge and consent. As far as I understand, that's how this kind of service usually gets implemented.
- lxgr 1y ago
  I assumed that that's how it works because I couldn't think of any other way to achieve the observed behavior, but pseudo roaming sounds plausible too, and presumably requires much less work on the carriers' side! Would that approach also allow the extra functionality they seem to be offering, such as only recently messaged numbers and emergency contacts being able to send messages to satellite users, though? I suppose they could just reject all MT-Forward-SM with sender numbers they don't like? > As far as I understand, that's how this kind of service usually gets implemented. Do you have any other examples for solutions like this? Are you thinking of (pre-VoWifi) carrier apps or services that could receive texts, sometimes on multiple devices?
  - miki123211 1y ago
    > Do you have any other examples for solutions like this I have a vague recollection that Pebble had something like this to get texts on the Pebble watch. > Would that approach also allow the extra functionality they seem to be offering, such as only recently messaged numbers and emergency contacts being able to send messages to satellite users, though? Hmm, you could definitely do this with a "Stripe-like" approach, where the actual traffic goes over the usual protocols to ease implementation, but the carriers provide Apple an API to query messaging history in some way (which they probably already offer in their apps, and so have good integrations for anyway). Stripe uses this pattern for fraud detection. Their card transactions still go over the antiquated ISO protocols from the 80's, because that's just what everybody integrates with and agrees on, but they can also speak a custom API directly with participating banks, mostly for better fraud detection and fraud-related information sharing.

magicalhippo 1y ago

4. Get a USB modem and hook it up to a computer somewhere safe that has coverage, and access it via internet. I'm building the opposite, using the modem and a Raspberry Pi to send me metrics from my cabin, but could easily work in reverse. While prototyping I had it parse SMS messages I sent it. Obviously not for everyone but we're on HN here...

Loudergood 1y ago

The real bonus to security here, access to your SMS is protected via MFA.