5 ms·

Makes me wonder, if emails and SMS messages start to carry more and more plaintext passwords (and links) providing direct access to everything, how will their s

by kennu 14y ago

Makes me wonder, if emails and SMS messages start to carry more and more plaintext passwords (and links) providing direct access to everything, how will their security hold up in the long run? I don't think they are inherently very secure channels.

peterwwillis 14y ago
They're not secure. SMS and e-mail are sent unauthenticated and unencrypted and can be intercepted in many different ways.
- numbsafari 14y ago
  For this reason, the link/code being sent should have an expiration attached to it, as well as being single-use. This doesn't avoid any number of different scenarios. Too bad we don't all use PGP for email...
  - sneak 14y ago
    If users could be trusted to maintain a key pair (PGP), then we wouldn't need to use email to do authentication.
- sneak 14y ago
  > SMS and e-mail are sent unauthenticated and unencrypted and can be intercepted in many different ways My SMS are encrypted with A5, and my email (gmail's inbound smtpd) is (usually) encrypted with TLS. Of course, I always check with TLS as well. It's not quite as bad as you seem to make it out.
  - tedunangst 14y ago
    I think people put way too much faith in inbound TLS. My mail server has some bozo self signed cert and nobody has ever failed to send me an email. Meaning: either nobody is using TLS to deliver mail or they use TLS and ignore all cert failures. Either way, about 99% less secure than you think it is.
    - mbq 14y ago
      Yeah; internal SMTP to SMTP traffic gives no guarantees at all. The only way is to use S-MIME or PGP.
  - peterwwillis 14y ago
    Which A5? Is it vulnerable to one of these attacks? https://en.wikipedia.org/wiki/A5/1#Security https://en.wikipedia.org/wiki/A5/1#Security (This is besides the more simple exploit, which is either cloning the handset or making a fake GSM base station which your phone will automatically hop to, pass traffic transparently, and sniff control channels) There is no such thing as secure transport-level e-mail because eventually it may [read: will] hop through a relay which does not use transport-level security. It's not secure, period.
    - chmod775 14y ago
      I don't think there is any working attack vector (i.e. not taking 100 years to do it) against pure TLS as of today. (using it along with compression is another thing) Edit: looks like I missed the point here Sent from mobile
numbsafari 14y ago
The thing is, those channels are already used by most services for password reset. So, a user could implement this workflow themselves already. Basically, create a password for the site that you don't even know yourself when you sign up. Make sure you select the appropriate "keep me logged in" option. Now, if you ever get logged out, go to a different computer or otherwise clear your cookie, you just "reset" your password... which generally involves sending you an email that lets you login to the site based on the link or code provided. This approach is simply making that the norm and doing away with the (probably insecure anyway) password for the site. If email and SMS aren't secure for password recovery, what alternatives do we have that scale and provide for a quick and user-friendly experience?
- sneak 14y ago
  This is actually the workflow I use every single time I log in to HN. I haven't the faintest idea what my password is.
  - peterwwillis 14y ago
    So..... Why don't you just save the password in your browser? Do you use a new computer every time you log into HN?
    - jackalope 14y ago
      With this approach, you don't have to store or remember your password. Just "reset and forget" whenever you want to start a new session. The only risk is in the few minutes your temporary password is in transit and sits in your inbox before you replace it with something ridiculously difficult to crack (or remember). It would be awesome if password reset pages offered the option of encrypting with a PGP public key to eliminate even that risk.
      - peterwwillis 14y ago
        With this approach, you're at risk every time you log in. Why on earth you want that I have no idea. If you create a ridiculously difficult to crack password once, you don't have to keep doing it. If it takes 50,000 years to crack, creating a new one 3 days later will not make you more secure. If you're going to the level of PGP to send yourself a new password every time you log in, just use client certs!!! Let me put this in more plain terms, because I want you to understand exactly why what you're doing is wrong. Now that I know you always reset your password, i'm going to find a way to intercept your e-mail. (There are many.) Then i'm going to automatically reset your password as soon as the mail is delivered, faster than you ever possibly could by hand. If you had just remembered or saved your password in the browser this would have been impossible. Now your account is compromised because you thought it was easier to go through 4 steps every time you log in versus just logging in with a saved password.
elchief 14y ago
Well, Google asked the NSA to help them with security. So if Google can't secure their mail, then we are all hooped anyway.
- icebraining 14y ago
  Google can only secure them (assuming you trust them, of course) from the moment it hits their servers. Until then, it's a postcard hopping from machine to machine.

by kennu 14y ago

peterwwillis 14y ago

They're not secure. SMS and e-mail are sent unauthenticated and unencrypted and can be intercepted in many different ways.

numbsafari 14y ago
For this reason, the link/code being sent should have an expiration attached to it, as well as being single-use. This doesn't avoid any number of different scenarios. Too bad we don't all use PGP for email...
- sneak 14y ago
  If users could be trusted to maintain a key pair (PGP), then we wouldn't need to use email to do authentication.
sneak 14y ago
> SMS and e-mail are sent unauthenticated and unencrypted and can be intercepted in many different ways My SMS are encrypted with A5, and my email (gmail's inbound smtpd) is (usually) encrypted with TLS. Of course, I always check with TLS as well. It's not quite as bad as you seem to make it out.
- tedunangst 14y ago
  I think people put way too much faith in inbound TLS. My mail server has some bozo self signed cert and nobody has ever failed to send me an email. Meaning: either nobody is using TLS to deliver mail or they use TLS and ignore all cert failures. Either way, about 99% less secure than you think it is.
  - mbq 14y ago
    Yeah; internal SMTP to SMTP traffic gives no guarantees at all. The only way is to use S-MIME or PGP.
- peterwwillis 14y ago
  Which A5? Is it vulnerable to one of these attacks? https://en.wikipedia.org/wiki/A5/1#Security https://en.wikipedia.org/wiki/A5/1#Security (This is besides the more simple exploit, which is either cloning the handset or making a fake GSM base station which your phone will automatically hop to, pass traffic transparently, and sniff control channels) There is no such thing as secure transport-level e-mail because eventually it may [read: will] hop through a relay which does not use transport-level security. It's not secure, period.
  - chmod775 14y ago
    I don't think there is any working attack vector (i.e. not taking 100 years to do it) against pure TLS as of today. (using it along with compression is another thing) Edit: looks like I missed the point here Sent from mobile

numbsafari 14y ago

The thing is, those channels are already used by most services for password reset. So, a user could implement this workflow themselves already. Basically, create a password for the site that you don't even know yourself when you sign up. Make sure you select the appropriate "keep me logged in" option. Now, if you ever get logged out, go to a different computer or otherwise clear your cookie, you just "reset" your password... which generally involves sending you an email that lets you login to the site based on the link or code provided. This approach is simply making that the norm and doing away with the (probably insecure anyway) password for the site. If email and SMS aren't secure for password recovery, what alternatives do we have that scale and provide for a quick and user-friendly experience?

sneak 14y ago
This is actually the workflow I use every single time I log in to HN. I haven't the faintest idea what my password is.
- peterwwillis 14y ago
  So..... Why don't you just save the password in your browser? Do you use a new computer every time you log into HN?
  - jackalope 14y ago
    With this approach, you don't have to store or remember your password. Just "reset and forget" whenever you want to start a new session. The only risk is in the few minutes your temporary password is in transit and sits in your inbox before you replace it with something ridiculously difficult to crack (or remember). It would be awesome if password reset pages offered the option of encrypting with a PGP public key to eliminate even that risk.
    - peterwwillis 14y ago
      With this approach, you're at risk every time you log in. Why on earth you want that I have no idea. If you create a ridiculously difficult to crack password once, you don't have to keep doing it. If it takes 50,000 years to crack, creating a new one 3 days later will not make you more secure. If you're going to the level of PGP to send yourself a new password every time you log in, just use client certs!!! Let me put this in more plain terms, because I want you to understand exactly why what you're doing is wrong. Now that I know you always reset your password, i'm going to find a way to intercept your e-mail. (There are many.) Then i'm going to automatically reset your password as soon as the mail is delivered, faster than you ever possibly could by hand. If you had just remembered or saved your password in the browser this would have been impossible. Now your account is compromised because you thought it was easier to go through 4 steps every time you log in versus just logging in with a saved password.

elchief 14y ago

Well, Google asked the NSA to help them with security. So if Google can't secure their mail, then we are all hooped anyway.

icebraining 14y ago
Google can only secure them (assuming you trust them, of course) from the moment it hits their servers. Until then, it's a postcard hopping from machine to machine.