5 ms·

PGP's ceremony is no solution for anything. A Signal-like experience (TOFU, key verification if you wish, alerts when keys change) would be superior, if people

by brnt 4y ago

PGP's ceremony is no solution for anything. A Signal-like experience (TOFU, key verification if you wish, alerts when keys change) would be superior, if people were trained more (and recall how hard is was to tell people to look for the green padlock). Autocrypt is an attempt (with little uptake). Certificates not only about encryption, but also about authority: am I really connected to my bank? PGP only solves that if I already have verified keys, which is the hardest part left unsolved. Unfortunately, proprietary two factor apps seems to be the way this is increasingly solved. Even further removed from a superior system (but, apparently, practical).

XorNot 4y ago
Most of the whole PGP system is inadequate for real use, but it points towards a model and interface which is: most people for most encryption simply want to know the answer to "is this my bank as my government/insurance company etc. believes it is?" and that sort of key would essentially be distributed by consensus. But the standard we've got is, once you're "in" to the CA root store, technically you can issue certificates for anything in any context, and the way we interact with them is to simply trust them uniformly. What we need is a system which let's us easily contextualize the actual trust problem we're solving with a connection: i.e. "I'm contacting a bank in <country>, so I want to know that the government of that country thinks its a bank, (maybe through the reserve bank of that country which expresses trust as to that identity". Chains of trust which make sense for the relationship. As it is, if I visit say - pm.gov.au and check the certificate I get that it was issued by GlobalSign. Who are they? Well, they're in the Root CA store which is why they're involved because that was the only requirement. But what I want to actually know is "Am I talking to the Australian government and at what level?"
- mschuster91 4y ago
  The problem isn't made easier by there being two completely distinct questions to be answered: - connection security: are the crypto credentials being used for signing e-mails or encrypting web traffic belonging to the entity in question? This should have been solved by putting the fingerprints into DNS so that clients can validate it on their own instead of having to trust a CA. DNSSEC and certificate pinning would have been the answer, but both are incredibly complex to set up and littered with failure scenarios that may be very difficult to recover from, but in the end it got "solved" by LetsEncrypt/ACME where the CA acts as a proxy. For e-mail, it got solved better by DKIM, but that's only applicable to the scenario "an email server wishes to check if an email it received from example.com actually originates from example.com", but not for "an email client wishes to send an encrypted email to foo@example.com and needs the public key for this mailbox". - connection authenticity: is the server a client is talking to (e.g. bank.com) actually belonging to the legal entity the user expects it to be? That one is what CAs were originally designed to verify and where a much larger amount of trust is placed on the CAs doing their job correctly. One idea to do that was SSL EV certificates, but for whatever reason these fell out of favor - and right now, there is no replacement at all for this use case. Additionally, the situation is made even more complex by legal or compliance requirements, e.g. banks who have to record virtually everything their employees do. For that, they have to break HTTPS by providing their own root certificate.
  - account42 4y ago
    Except the questions are not distinct as long as you want to protect against MITM attacks. Having a secure connection is meaningless if you have no way of telling that its secure up until whoever you intend to talk to. And if you do trust the connection to be free from active attackers then you don't need certificates at all, e.g. diffie helman key exchange would be enough to create a shared secret that in the presence of a passive adversary that can only observe.
bombolo 4y ago
> PGP only solves that if I already have verified keys, which is the hardest part left unsolved. But you've opened your bank account in person. When you got the token to login to the bank website they might as well ask you to sign their certificate since you are there.
- joshuaissac 4y ago
  > But you've opened your bank account in person. Many banks do not require this. Many do not even have physical branches to visit.
- mort96 4y ago
  Last time I opened a bank account, I did it by creating an account on their website.
  - bombolo 4y ago
    USA I suppose? I guess that's why you have a huge problem of people opening debt under other people's name there, which is a thing that doesn't really happen here.
    - mort96 4y ago
      Norway. I don't believe we have that problem.
    - brnt 4y ago
      Most European countries run proper citizen registries that allow for secure verification of IDs and online opening of bank accounts. Many banks don't require visits anymore. All the same, two factor devices (you can mail them too) are phased out across the blad in favor of mobile apps. Which is nog great.
      - bombolo 4y ago
        mobile authentication is actually in violation of a EU directive. My bank linked that very directive when they retired the physical token in favour of using the phone, saying the bad EU was forcing them to do this money saving step. I couldn't believe it was true, I read the actual text of the directive and it was in fact not true.
upofadown 4y ago
I would not want to trust my bank account to all of the following: * the people that run the Signal Servers (or whoever). * The people that send the verification SMS. * The phone company. ... even for a little while. Two factor only verifies you, not the bank.
- lotsofpulp 4y ago
  Does TOTP 2FA solve not having to trust those other entities?
  - bombolo 4y ago
    Many force you to install their own app instead of using a generic one. Which is a problem. Also google's app doesn't easily let you export and backup the seeds. So you either remember to do that initially or breaking your phone == losing access to everything.
    - account42 4y ago
      > Many force you to install their own app instead of using a generic one. Which is a problem. I agree that having to use a proprietary app is not great, but TOTP is vulnerable to MITM attacks because the tokens are not restricted to a specific action but only to a time slice. For many use cases that is not a big problem, but for a bank account I'd want more security. Of course being able to do your banking in the same app or a slightly different one on the same device kind of defeats the purpose.

by brnt 4y ago

XorNot 4y ago

Most of the whole PGP system is inadequate for real use, but it points towards a model and interface which is: most people for most encryption simply want to know the answer to "is this my bank as my government/insurance company etc. believes it is?" and that sort of key would essentially be distributed by consensus. But the standard we've got is, once you're "in" to the CA root store, technically you can issue certificates for anything in any context, and the way we interact with them is to simply trust them uniformly. What we need is a system which let's us easily contextualize the actual trust problem we're solving with a connection: i.e. "I'm contacting a bank in <country>, so I want to know that the government of that country thinks its a bank, (maybe through the reserve bank of that country which expresses trust as to that identity". Chains of trust which make sense for the relationship. As it is, if I visit say - pm.gov.au and check the certificate I get that it was issued by GlobalSign. Who are they? Well, they're in the Root CA store which is why they're involved because that was the only requirement. But what I want to actually know is "Am I talking to the Australian government and at what level?"

mschuster91 4y ago
The problem isn't made easier by there being two completely distinct questions to be answered: - connection security: are the crypto credentials being used for signing e-mails or encrypting web traffic belonging to the entity in question? This should have been solved by putting the fingerprints into DNS so that clients can validate it on their own instead of having to trust a CA. DNSSEC and certificate pinning would have been the answer, but both are incredibly complex to set up and littered with failure scenarios that may be very difficult to recover from, but in the end it got "solved" by LetsEncrypt/ACME where the CA acts as a proxy. For e-mail, it got solved better by DKIM, but that's only applicable to the scenario "an email server wishes to check if an email it received from example.com actually originates from example.com", but not for "an email client wishes to send an encrypted email to foo@example.com and needs the public key for this mailbox". - connection authenticity: is the server a client is talking to (e.g. bank.com) actually belonging to the legal entity the user expects it to be? That one is what CAs were originally designed to verify and where a much larger amount of trust is placed on the CAs doing their job correctly. One idea to do that was SSL EV certificates, but for whatever reason these fell out of favor - and right now, there is no replacement at all for this use case. Additionally, the situation is made even more complex by legal or compliance requirements, e.g. banks who have to record virtually everything their employees do. For that, they have to break HTTPS by providing their own root certificate.
- account42 4y ago
  Except the questions are not distinct as long as you want to protect against MITM attacks. Having a secure connection is meaningless if you have no way of telling that its secure up until whoever you intend to talk to. And if you do trust the connection to be free from active attackers then you don't need certificates at all, e.g. diffie helman key exchange would be enough to create a shared secret that in the presence of a passive adversary that can only observe.

bombolo 4y ago

> PGP only solves that if I already have verified keys, which is the hardest part left unsolved. But you've opened your bank account in person. When you got the token to login to the bank website they might as well ask you to sign their certificate since you are there.

joshuaissac 4y ago
> But you've opened your bank account in person. Many banks do not require this. Many do not even have physical branches to visit.
mort96 4y ago
Last time I opened a bank account, I did it by creating an account on their website.
- bombolo 4y ago
  USA I suppose? I guess that's why you have a huge problem of people opening debt under other people's name there, which is a thing that doesn't really happen here.
  - mort96 4y ago
    Norway. I don't believe we have that problem.
  - brnt 4y ago
    Most European countries run proper citizen registries that allow for secure verification of IDs and online opening of bank accounts. Many banks don't require visits anymore. All the same, two factor devices (you can mail them too) are phased out across the blad in favor of mobile apps. Which is nog great.
    - bombolo 4y ago
      mobile authentication is actually in violation of a EU directive. My bank linked that very directive when they retired the physical token in favour of using the phone, saying the bad EU was forcing them to do this money saving step. I couldn't believe it was true, I read the actual text of the directive and it was in fact not true.

upofadown 4y ago

I would not want to trust my bank account to all of the following: * the people that run the Signal Servers (or whoever). * The people that send the verification SMS. * The phone company. ... even for a little while. Two factor only verifies you, not the bank.

lotsofpulp 4y ago
Does TOTP 2FA solve not having to trust those other entities?
- bombolo 4y ago
  Many force you to install their own app instead of using a generic one. Which is a problem. Also google's app doesn't easily let you export and backup the seeds. So you either remember to do that initially or breaking your phone == losing access to everything.
  - account42 4y ago
    > Many force you to install their own app instead of using a generic one. Which is a problem. I agree that having to use a proprietary app is not great, but TOTP is vulnerable to MITM attacks because the tokens are not restricted to a specific action but only to a time slice. For many use cases that is not a big problem, but for a bank account I'd want more security. Of course being able to do your banking in the same app or a slightly different one on the same device kind of defeats the purpose.