## Will 2FA, in general, be bypassed by a stolen passport?

You have a friend called Bob.

You have a copy of Bob’s passport.

Bob uses 2FA for all of his accounts.

Would you, in general, be able to bypass this 2FA and access his accounts, by doing the following:

• Emailing support

• Sending support a copy of Bob’s passport, claiming that you are, indeed, Bob

Would it be fair to say that the majority of support agents would reset 2FA on Bob’s account?

## Does Type:Type lead to inconsistency without general inductive types?

In e.g. Agda , it is possible to derive an element of the empty type by enabling the “type in type” option.

Every proof I have seen (and come up with) involves making a special inductive type definition. Can a contradiction be derived using type in type but with e.g. only using standard library types?

## Why doesn’t my government, and governments in general, provide useful statistics in digital format? [closed]

I live in Sweden, but this applies to all other countries as well.

I have a general interest in, and fascinations of, statistics and working with data in databases. By far the biggest obstacle has nothing to do with technically dealing with the database software, writing SQL queries, or designing databases. Rather, the #1 problem is:

Nobody wants to provide useful data!

I have spent a significant part of the last 20 years searching for databases/data files of all kinds. Time and time again, I end up at a “contact us for pricing” webpage, or a “Buy now for only $4,799!” text. Oddly, this does not just apply to commercial entities, but also authorities. Even though the Swedish government has been talking about “open data” and “free information for all” for a very long time, the actual reality is that virtually none of that juicy data is available for you and I to grab and use. Instead, they have multiple layers of “red tape”, requiring you to pay through the nose for any kind of access, and in many cases, you aren’t even allowed to pay for it unless you run a major corporation with special ties to the government. It’s really bizarre. The data they do allow you to look at is meaningless/shallow statistics, rarely if ever provided in a format which can be reasonably parsed by a computer and fed into my database for further analysis. The so-called “open data for everyone” often consists of nothing more than a bunch of formatted PDFs, useless for my purposes. I’m not interested in static columns showing how many new people were born in 2020. I want a list of those people, with their names, genders, race, blood type, etc. I realize that all data cannot be open without heavy abuse inevitably resulting from it. However, at least the Swedish government has this idea of “public records”, where you are theoretically allowed to request all kinds of data. The problem is that they only allow you to do this in person, over phone or via e-mail, and you have to do it manually and only request at most three (3) “units” each time. In practice, this makes it useless unless. If this information is allegedly “public”, why are they so unwilling to actually make it available? I could send an e-mail to a Swedish government entity right now, requesting all kinds of information (including their full social security number) for a given person, and they will respond within 24 hours with it, no questions asked. I’ve done it many times. However, if I ask them for a Swedish_people.csv file with every person registered in Sweden and the same information I requested manually for one or up to three persons, they will refuse. Major corporations are able to pay a lot of money to get access to their government APIs, but it costs a fortune and they wouldn’t let me buy access to it even if I had the money (because I don’t run a major company). It doesn’t make any sense to me. I wonder why they have these double standards, and how they can possibly charge money for “public” records. A dream of mine would be to be able to do: SELECT name, email_address, physical_address, passport_photo FROM people WHERE current_city =$  1 AND gender = $2 AND age >=$  3 AND age <= $4 AND civil_status =$  5 ORDER BY distance_from_me DESC; 

Of course, this is completely unrealistic, but you get the idea. I wish to have actual, curated records from (semi) trusted sources rather than having to play with the few, measly databases which are freely available to the public at no charge.

A perfect example of something very basic would be the telephone book. Back in the day, they sent out a complete book of every single person’s name, telephone number and address to every household in the entire country. This was standard practice all over the world, I believe. A digital version of that would be a .csv file which I could just download from a government website at a static URL, always kept updated. Nope. Nothing like that. I’m forced to use these third-party, commercial websites where I get to enter individual people’s names and send this information to the company in question. They are paying the government a lot of money to get this information, even though it could be made available for virtually no cost at all.

Why, since they used to provide this information in physical form, is it now unthinkable in the digital age?

## how many parameters do we need to estimate for a general probabilistic model

Its a question from a test in machine learning. I have 3 binary variables x1,x2 and x3, each one of them has a binary output y (can be 0 or 1). for a general probabilistic classifier, how many parameters do we need to in order to estimate it?

I saw that the answer is 16 but I dont know why

## 3-Approximation for General position subset

I am currently studying for an exam and stumbled upon the following task: Given the following problem:

Input A set of points $$P \subseteq \mathcal{Q}^2$$ and $$k \in \mathbb{N}$$

Question Find the maximum subset $$S \subseteq P$$ such that no three points in $$S$$ are collinear.

The task is to find a polynomial time 3-approximation algorithm that is an algorithm that deletes at most $$3$$-times as many points as an optimal solution. Unfortunately, I am totally clueless here. How would such an algorithm look like?

## PCI Idle Session Timeout general question

Can someone help me understand how the PCI Timeout rules change for an application like the Starbucks App? A user is able to keep their card open ready for scan for longer the 15 minutes if needed, but PCI A11y AA also requires to display a message giving the user a chance to react and keep the session alive.

I understand and have implemented it from an e-commerce approach but am a bit confused on the e-wallet approach.

## Is there a general consensus about not combining Unearthed Arcana (UA) materials with multi-classing?

Is there a general consensus about not combining Unearthed Arcana (UA) materials with multi-classing?

I have come across posts where contributors (in the comments) state that you cannot use a particular feature from Unearthed Arcana (UA) because the player had already chosen to multi-class.

Where does this notion come from?

I realise the DM has the final say on this, but is there an official statement in the published materials or a tweet to support this, or is it merely based on opinion?

The main argument I’ve seen is this: It is UA material and not part of the main set of rules yet; it has not been adjusted for multi-classing. Therefore players who multi-class are not be allowed to use materials from UA.

## General: firmware reversal

I’m not any sort of expert in this, i’m only interested

I saw a video about firmware extractin through JTAG, and it ended up with the plane filesystem, all right!

but then what? why all of this? what can I do with the filesystem? I’m looking for something to get interested in, but it only get to the point of having the filesystem

The number of possible heaps that are full binary trees of height $$h$$ and can be formed with ($$n = 2^h – 1$$) distinct elements can be computed by recursion: $$a_h = {2^h – 2 \choose 2^{h – 1} – 1} a_{h – 1}^2$$ How to compute the general term formula with this recursion formula?