FYI: FAQ Some people on the waitlist have expressed interest in more details, and since we have not yet gotten around to update the website, here's more background info:

Why did it take so long?

The reason this took so long is that we were hoping to work directly with one or multiple carriers, but totally misjudged just how long and how difficult it would be to find a solution that works

We changed our approach now from trying to build this ourselves to relying more on third parties (basically, one per country code), so that we focus more on the actual UX in the app and less on technical GSM network details.

We are still talking with carriers, and will continue to do so, but with an open timeline and no due dates.

What do I get?

You get German mobile phone number, accessible via the Daito web interface. Mobile phone numbers in Germany have specific network codes (mostly 17x or 15x) assigned to them, and are clearly identifiable by the number alone. Also, mobile phones are not regionally assigned, but country-wide. (Therefore, it's not possible to get a mobile phone number from e.g. Berlin.)

Why do you only offer SIM-based numbers and not VOIP-based numbers?

Because all VOIP-based providers and numbers that we tested had reliability issues.

All big tech corps (Google, Microsoft, Apple & others) have untold stories of unreliable & unsatisfactory UX when it comes to using VOIP numbers for 2FA. We, like many others, started with Twilio (a leading VOIP provider) when we began working on this topic and were surprised just how hard it is to get a reliable experience going. Twilio even has a list of cases in der support docs for when they can not guarantee receival of an SMS. This is sometimes related to roaming, then about SMS delivery routing, then about national regulations, then again because SMS is only a "best effort protocol" or because VOIP providers simply can not handle alphanumeric sender IDs, such as "Linkedin" or "Amazon" instead of e.g +441768450844.

Phone numbers based on physical SIM cards play in a different league compared to VOIP numbers.

When do I get a number from country XYZ?

Too many factors decide this (most of them regulatory) and thus we will not give an estimate when we will have this.

What about number recycling?

We and our upstream provider can not guarantee that a phone number has not yet been in use before. However,

What about unwanted SMS or spam

The 6 months wait time is to identify numbers that still receive traffic. It would be very unusual to get unwanted SMS, e.g. an automated spam campaign.

What however is possible is that you receive SMS that are the result of typos, e.g. somebody entering his phone number somewhere but mixing up a number. Those SMS are very rare and not a regular occurence.

What about SIM jacking?

I am very happy to tell you that this is not possible at all. :)

These SIMs are not regular B2C SIMs, but part of a B2B contract. SIM & number assignments can't be done over the phone (social engineering attacks etc.), but require change requests in writing (from you to us, from us to our upstream provider, from there to the carrier) or access to very specific B2B management interfaces.

While this secures the SIM/number assignment, it also means that you can not port a number to another carrier since this is locked.

What carrier are you using?

We use T-Mobile Germany, with automatic roaming to Vodafone or Telefonica o2 (our 3 main carriers in Germany) should T-Mobile's network fail for whatever reason.

(Note to non-Germans: T-Mobile Germany is the largest carrier in Germany and regularly wins prizes for the most reliable mobile phone network.)

How reliable is network reception?

The SIMs connect to the network from the downtown area of a medium-sized city in northern Germany, with several GSM network towers in the vicinity. Definitely no issues with being in the countryside, having spotty reception, etc.

How reliable is SMS receival?

In general, as reliable as if it would be your own phone. Except now the phone is, basically, on someone else's desk.

Can you guarantee high availability?

Having a single SIM linked to a phone number is a single point of failure and there is no technical measure available to (e.g. cloning SIMs & numbers, then hosting them in 2 data centers) to change that. So, no, there is no technical solution available to offer a high availability (e.g. including automatic failover etc) solution to you.

Note: This is one of the topics we are discussing with carriers, how we can get rid of phyiscal SIM's all together but not having to use VOIP numbers. Very technical discussions and lots of "this is not how this is supposed to work"

While we are very confident in our solution and product we strongly advise to ensure backup authentication methods should there be any issues.

What about maintenance windows?

Maintenance windows are planned at least a week in advance and scheduled for the weekend.

What about the pricing?

A phone number will be a seperate subscription of $49 with a monthly duration. No setup fees or anything else. This subscription requires a paid Daito subscription at the "Startup" tier (incl. 10 users) as a minimum and will be available as an add-on.

Note: $49/month is our introductionary price and it will definitely go up in 2023.

What about privacy, security, encryption?

SMS are received on the technical infrastructure of our hosting provider, from which we process it for your until you see it in the Daito web-interface. We receive SMS unencrypted, but (of course) transfer them encrypted (encryption in transit, using TLS) and encrypt them when stored (encryption at rest, using AES). We will add more encryption in the future to ensure highest levels of security.