17 ms·

P2P, Encrypted Email Protocol

97 points by gbrindisi 13y ago

AndrewDucker 13y ago
If it's P2P then I'm back to running my own server - and if you run your own server then email is already P2P.
- autotravis 13y ago
  But setting up a mail server is more difficult than firing up a piece of P2P software.
  - AndrewDucker 13y ago
    True. But servers have advantages, like being able to get to my email from anywhere. I remember the dark days of POP...
  - chimeracoder 13y ago
    Not really - setting up a mail server is actually pretty easy if you ignore spam detection algorithms. Email/SMTP is a very fault-tolerant protocol, which means it's very forgiving to a whole number of different errors that you can make while setting it up. The problem comes when you account for the facts such as (1) some ISPs block ports commonly used for email; (2) some email providers will mark email from self-hosted email servers as spam. But none of that is about email/SMTP specifically (and could theoretically apply to any P2P solution that catches on).
omh 13y ago
It seems like it would be relatively easy to perform traffic analysis of this protocol. If you can see the traffic of a reasonable number of nodes (as I'm sure the NSA can) then can't you just watch the messages being inserted and retrieved and work out who the sender and recipient is? Obviously this doesn't help with the content of the message, but in many cases just knowing who's talking to whom is a good part of what you want to keep secret.
- naughtysriram 13y ago
  What if the tool automatically sends a new public key for next message within every current message? Or the public key can be recycled after certain period of use say 1 week. Would this make the emails look anonymous or still can be tracked?
- tux 13y ago
  Unless you're using your real name this should not be a problem. Also many will use this client with VPN/Proxy.
  - omh 13y ago
    In that respect it's not much better than just anonymously signing up for gmail via a VPN.
- adouzzy 13y ago
  You can pretend reading ,say 1M, emails passed by. I mean you can only understand those you can encrypted. But there is no way to analysis which emails have you encrypted through traffic analysis. The best way to get invisible is to get into the crowd :)
- kansface 13y ago
  This is just an encryption scheme. It does not provide anonymity. Truly anonymous email would not be good for spam.
Steuard 13y ago
I've read chunks of the site, but I'm still not entirely clear on what advantage this scheme has over RSA encryption of standard SMTP mail (via PGP/MIME on the local machine, say). Is the main advantage that a given identity isn't tied to a specific server here? Is that a big enough gain to justify an entirely new protocol and ecosystem of clients? I assume I'm missing some other benefits.
- delinka 13y ago
  P2P reduces points of failure. Sure, you can encrypt email to your heart's content, but can you trust the server you dropped it with to deliver it? "Why would anyone want to prevent you emailing people?" you ask. Lots of reasons, the biggest of which seems to me to be that if you can't trust encrypted mail to arrive, perhaps you'll abandon it.
- zokier 13y ago
  SMTP leaks metadata.
  - qznc 13y ago
    How does this p2p approach avoid that?
  - bcl 13y ago
    Only if the servers aren't using SMTPS. Which in practice many don't but there really is no reason why that cannot be changed.
    - ape4 13y ago
      If yourserver.com is connecting to friendsserver.com on port 25... there is some metadata. I mean if three-letter-agencies are monitoring the internet they'll figure out what just happened.
- ye 13y ago
  You still need a way to exchange the RSA encryption keys with each sender and receiver.
ugexe 13y ago
So this allows potential crackers to save every copy of every encrypted email, allowing them to be cracked in the future when there is increased computer power and more advanced cracking techniques/rainbow tables?
- qznc 13y ago
  How would you prevent this? It is not prevented by SMTP and not by this p2p approach.
  - ugexe 13y ago
    This puts your email in everyone's hands, it's just encrypted so it probably can't be read without the key (yet). Regular email does not do this.
    - qznc 13y ago
      So its "everyone" for p2p vs "many secret services" for SMTP. On the upside, it gives every user a good incentive to use good encryption.
    - Karunamon 13y ago
      On the positive side, it's unlikely "everyone" who isn't a government agency with billions of dollars of taxpayer money to waste has the time, storage, and compute resources to mount the kind of attack you're talking about. I know NSA is the topic of the day, but they're kind of a special case here. They're the single most powerful and well funded adversary the average crypto user will face.
      - tedunangst 13y ago
        Until you break up and your ex decides to publish your key in revenge. Unlike a password, you can't change a key and revoke access.
        Karunamon 13y ago
ape4 13y ago
This is a nice try. I would like to see some incremental improvements in mail. For example in the header we could display a rating of how secure the mail is. Based use of TLS, etc. If client programs displayed this it would encourage infrastructure improvements.
pampa 13y ago
Any proof of concept source code yet?
frank_boyd 13y ago
Is this about re-inventing the wheel again? http://retroshare.sourceforge.net/ http://retroshare.sourceforge.net/ does encrypted p2p for "email"/chat/VOIP/file sharing/forums/etc.
- dingdingdang 13y ago
  Thanks for mentioning retroshare, it is a VERY decent system. Still, I reckon there's quite a bit of mileage in doing -one thing- right; retroshare's fix-it-all-in-one-package may not appeal to everybody.
sirsar 13y ago
So it's like Bitmessage, but without an implementation?
- johnchristopher 13y ago
  I also thought they already had a working client. The wording is misleading: "FlowingMail is the name of a new decentralized messaging protocol, while FlowingMail Client is an email client that uses the protocol."
Osmium 13y ago
Speaking of the need for a more secure email, I just want to share an anecdote that blew my mind recently. I was trying to pay for something with a major tech company but they were having problems with my card, so they emailed me my card details to check they were correct! I'd be tempted to name and shame them, but it's not really their fault as much as it is the specific person, because I find it hard to believe people aren't trained not to do that. Makes me think that all customer support emails should be regex'd for credit card numbers and if they're found their mail servers shouldn't allow them to be sent... In any case, the whole institution of email is a security nightmare. I doubt this is the solution, but there certainly needs to be one, and as much for "normal" people as anyone else. We all have information that needs to be kept secure.
- showerst 13y ago
  I've actually worked for someone who had a company-wide email filter for credit card numbers and SSNs. It was frustrating because it would occasionally catch license keys or foreign phone numbers, but probably a good idea for some groups.
- corobo 13y ago
  In the era of automatic payment processing I can't think of any reason why a member of staff should have access to anything other than the last 4 digits, name and address for verifying it's the correct card
- adambard 13y ago
  I've been trying to get some identity documents (birth certificate, marriage certificate) translated recently. Every place I've contacted wanted me to just email them scans of the documents, that will presumably sit on their ISP's server in plaintext indefinitely. I definitely think there's something to a messaging protocol that's simply not able to be insecure.
kgo 13y ago
This seems very similar to bitmessage, which has a functioning client and 1000's of active nodes. Why would I wait for this instead of using bitmessage?
- yapcguy 13y ago
  Read the Bitmessage white paper and you'll know why you should avoid Bitmessage: Every node will have a copy of every single message sent across the entire network. I believe the meme to use here is "Fail".
  - pampa 13y ago
    Care to explain why you think it is a fail?
    - jnbiche 13y ago
      Yes, it's not scalable. Even the Bitmessage creator acknowledges this. They've been at an impasse for quite a while trying to come up with a better system with which to scale.
      - 18pfsmt 13y ago
        I realize not reading Bitmessage's documentation is lazy, but could you explain the inability to scale such a system? Is it simply the chicken or the egg dilemma of nobody using it currently (and so, pretty much the same issue BitTorrent originally had)? Or is it some technical reason?
        quantumpotato_ 13y ago
        Every node has a copy of every message. If the whole internet used this, everyone would have a copy of every (encrypted) email.
        18pfsmt 13y ago
mknits 13y ago
Retroshare already do that.
lectrick 13y ago
I'm moving on until I see a link to some open-source code. With a test suite.
Vektorweg 13y ago
If xmpp would be more secure, it would be a good replacement for email. Using multiple xmpp servers would give a comparable advantage to p2p email.
- marquis 13y ago
  I wasn't aware XMPP wasn't secure? It supports TLS, SSL, OTR and more. Are there known issues?
  - zanny 13y ago
    I was under this impression too. I really like Jingle for encrypted voice calls, but if that is vulnerable I'd want to know!
  - Vektorweg 13y ago
    The only problem is, that the server can see all messages. OTR solves this problem, but who use it? OTR would even solve the e-mail issue.
    - marquis 13y ago
      XMPP supports signing of messages, and for push notifications OTR is great.
nightcracker 13y ago
I've been looking at similar ideas lately, but I simply do not know how to defeat the Sybil attack =/ A centralized certificate authority is necessary to keep a functioning system, as far as I can see.
mic159 13y ago
If I understand correctly, there is a key in the DHT that is effectively a list of pointers to all your mail? If so, an attacker could control your inbox by starting a bunch of nodes around that key, couldn't they? To disable a persons mail, you would start up some altered nodes around the address space you want to attack, have them respond normally until you control enough or all of the nodes covering the target address. Then flip a switch that makes them all start saying that inbox is empty. Then start backing off your nodes, and replacement regular nodes would replicate your altered state. Would this be possible? Or am I missing something?

97 points by gbrindisi 13y ago

AndrewDucker 13y ago

If it's P2P then I'm back to running my own server - and if you run your own server then email is already P2P.

autotravis 13y ago
But setting up a mail server is more difficult than firing up a piece of P2P software.
- AndrewDucker 13y ago
  True. But servers have advantages, like being able to get to my email from anywhere. I remember the dark days of POP...
- chimeracoder 13y ago
  Not really - setting up a mail server is actually pretty easy if you ignore spam detection algorithms. Email/SMTP is a very fault-tolerant protocol, which means it's very forgiving to a whole number of different errors that you can make while setting it up. The problem comes when you account for the facts such as (1) some ISPs block ports commonly used for email; (2) some email providers will mark email from self-hosted email servers as spam. But none of that is about email/SMTP specifically (and could theoretically apply to any P2P solution that catches on).

omh 13y ago

It seems like it would be relatively easy to perform traffic analysis of this protocol. If you can see the traffic of a reasonable number of nodes (as I'm sure the NSA can) then can't you just watch the messages being inserted and retrieved and work out who the sender and recipient is? Obviously this doesn't help with the content of the message, but in many cases just knowing who's talking to whom is a good part of what you want to keep secret.

naughtysriram 13y ago
What if the tool automatically sends a new public key for next message within every current message? Or the public key can be recycled after certain period of use say 1 week. Would this make the emails look anonymous or still can be tracked?
tux 13y ago
Unless you're using your real name this should not be a problem. Also many will use this client with VPN/Proxy.
- omh 13y ago
  In that respect it's not much better than just anonymously signing up for gmail via a VPN.
adouzzy 13y ago
You can pretend reading ,say 1M, emails passed by. I mean you can only understand those you can encrypted. But there is no way to analysis which emails have you encrypted through traffic analysis. The best way to get invisible is to get into the crowd :)
kansface 13y ago
This is just an encryption scheme. It does not provide anonymity. Truly anonymous email would not be good for spam.

Steuard 13y ago

I've read chunks of the site, but I'm still not entirely clear on what advantage this scheme has over RSA encryption of standard SMTP mail (via PGP/MIME on the local machine, say). Is the main advantage that a given identity isn't tied to a specific server here? Is that a big enough gain to justify an entirely new protocol and ecosystem of clients? I assume I'm missing some other benefits.

delinka 13y ago
P2P reduces points of failure. Sure, you can encrypt email to your heart's content, but can you trust the server you dropped it with to deliver it? "Why would anyone want to prevent you emailing people?" you ask. Lots of reasons, the biggest of which seems to me to be that if you can't trust encrypted mail to arrive, perhaps you'll abandon it.
zokier 13y ago
SMTP leaks metadata.
- qznc 13y ago
  How does this p2p approach avoid that?
- bcl 13y ago
  Only if the servers aren't using SMTPS. Which in practice many don't but there really is no reason why that cannot be changed.
  - ape4 13y ago
    If yourserver.com is connecting to friendsserver.com on port 25... there is some metadata. I mean if three-letter-agencies are monitoring the internet they'll figure out what just happened.
ye 13y ago
You still need a way to exchange the RSA encryption keys with each sender and receiver.

ugexe 13y ago

So this allows potential crackers to save every copy of every encrypted email, allowing them to be cracked in the future when there is increased computer power and more advanced cracking techniques/rainbow tables?

qznc 13y ago
How would you prevent this? It is not prevented by SMTP and not by this p2p approach.
- ugexe 13y ago
  This puts your email in everyone's hands, it's just encrypted so it probably can't be read without the key (yet). Regular email does not do this.
  - qznc 13y ago
    So its "everyone" for p2p vs "many secret services" for SMTP. On the upside, it gives every user a good incentive to use good encryption.
  - Karunamon 13y ago
    On the positive side, it's unlikely "everyone" who isn't a government agency with billions of dollars of taxpayer money to waste has the time, storage, and compute resources to mount the kind of attack you're talking about. I know NSA is the topic of the day, but they're kind of a special case here. They're the single most powerful and well funded adversary the average crypto user will face.
    - tedunangst 13y ago
      Until you break up and your ex decides to publish your key in revenge. Unlike a password, you can't change a key and revoke access.
      - Karunamon 13y ago

ape4 13y ago

This is a nice try. I would like to see some incremental improvements in mail. For example in the header we could display a rating of how secure the mail is. Based use of TLS, etc. If client programs displayed this it would encourage infrastructure improvements.

pampa 13y ago

Any proof of concept source code yet?

frank_boyd 13y ago

Is this about re-inventing the wheel again? http://retroshare.sourceforge.net/ http://retroshare.sourceforge.net/ does encrypted p2p for "email"/chat/VOIP/file sharing/forums/etc.

dingdingdang 13y ago
Thanks for mentioning retroshare, it is a VERY decent system. Still, I reckon there's quite a bit of mileage in doing -one thing- right; retroshare's fix-it-all-in-one-package may not appeal to everybody.

sirsar 13y ago

So it's like Bitmessage, but without an implementation?

johnchristopher 13y ago
I also thought they already had a working client. The wording is misleading: "FlowingMail is the name of a new decentralized messaging protocol, while FlowingMail Client is an email client that uses the protocol."

Osmium 13y ago

Speaking of the need for a more secure email, I just want to share an anecdote that blew my mind recently. I was trying to pay for something with a major tech company but they were having problems with my card, so they emailed me my card details to check they were correct! I'd be tempted to name and shame them, but it's not really their fault as much as it is the specific person, because I find it hard to believe people aren't trained not to do that. Makes me think that all customer support emails should be regex'd for credit card numbers and if they're found their mail servers shouldn't allow them to be sent... In any case, the whole institution of email is a security nightmare. I doubt this is the solution, but there certainly needs to be one, and as much for "normal" people as anyone else. We all have information that needs to be kept secure.

showerst 13y ago
I've actually worked for someone who had a company-wide email filter for credit card numbers and SSNs. It was frustrating because it would occasionally catch license keys or foreign phone numbers, but probably a good idea for some groups.
corobo 13y ago
In the era of automatic payment processing I can't think of any reason why a member of staff should have access to anything other than the last 4 digits, name and address for verifying it's the correct card
adambard 13y ago
I've been trying to get some identity documents (birth certificate, marriage certificate) translated recently. Every place I've contacted wanted me to just email them scans of the documents, that will presumably sit on their ISP's server in plaintext indefinitely. I definitely think there's something to a messaging protocol that's simply not able to be insecure.

kgo 13y ago

This seems very similar to bitmessage, which has a functioning client and 1000's of active nodes. Why would I wait for this instead of using bitmessage?

yapcguy 13y ago
Read the Bitmessage white paper and you'll know why you should avoid Bitmessage: Every node will have a copy of every single message sent across the entire network. I believe the meme to use here is "Fail".
- pampa 13y ago
  Care to explain why you think it is a fail?
  - jnbiche 13y ago
    Yes, it's not scalable. Even the Bitmessage creator acknowledges this. They've been at an impasse for quite a while trying to come up with a better system with which to scale.
    - 18pfsmt 13y ago
      I realize not reading Bitmessage's documentation is lazy, but could you explain the inability to scale such a system? Is it simply the chicken or the egg dilemma of nobody using it currently (and so, pretty much the same issue BitTorrent originally had)? Or is it some technical reason?
      - quantumpotato_ 13y ago
        Every node has a copy of every message. If the whole internet used this, everyone would have a copy of every (encrypted) email.
        18pfsmt 13y ago

mknits 13y ago

Retroshare already do that.

lectrick 13y ago

I'm moving on until I see a link to some open-source code. With a test suite.

Vektorweg 13y ago

If xmpp would be more secure, it would be a good replacement for email. Using multiple xmpp servers would give a comparable advantage to p2p email.

marquis 13y ago
I wasn't aware XMPP wasn't secure? It supports TLS, SSL, OTR and more. Are there known issues?
- zanny 13y ago
  I was under this impression too. I really like Jingle for encrypted voice calls, but if that is vulnerable I'd want to know!
- Vektorweg 13y ago
  The only problem is, that the server can see all messages. OTR solves this problem, but who use it? OTR would even solve the e-mail issue.
  - marquis 13y ago
    XMPP supports signing of messages, and for push notifications OTR is great.

nightcracker 13y ago

I've been looking at similar ideas lately, but I simply do not know how to defeat the Sybil attack =/ A centralized certificate authority is necessary to keep a functioning system, as far as I can see.

mic159 13y ago

If I understand correctly, there is a key in the DHT that is effectively a list of pointers to all your mail? If so, an attacker could control your inbox by starting a bunch of nodes around that key, couldn't they? To disable a persons mail, you would start up some altered nodes around the address space you want to attack, have them respond normally until you control enough or all of the nodes covering the target address. Then flip a switch that makes them all start saying that inbox is empty. Then start backing off your nodes, and replacement regular nodes would replicate your altered state. Would this be possible? Or am I missing something?