this vs protonmail.ch?
I'm going with protonmail, personally.
Lavabit Reloaded
181–190 of 240 posts
Re: Lavabit Reloaded
#182Earlier quoted context omitted.
> > Search isn't possible > It absolutely is, in both theory and practice. The server stores an encrypted index, and the client walks it (requesting parts as needed). It's going to little slower, and a lot more complex but it's doable. Are you suggesting that to search your mailbox, the client should download every single encrypted message in the entire mailbox and decrypt them all locally to search them? If not, how…
The search doesn't happen on the server. The client (e.g. desktop client) indexes the messages and encrypts the index. Then, when another client (e.g. mobile client) wants to search for a message, it downloads the index, searches it, and then pulls down the appropriate message(s).
If an attacker can tell which part of the index was modified, that gives them enough information to decrypt the index and e-mails.
Clients would always have to download+upload the full index (which needs to be re-encrypted with a new IV). This is a huge problem - the index can easily be hundreds of MB for a large mailbox.
Re: Lavabit Reloaded
#183Earlier quoted context omitted.
They can be blackmailed but can't be gagged as any request for a person's data (including access to it) from a Swiss company MUST go through Swiss court. And even gag orders can't compel someone to break the law. Same situation as three letter agencies requesting EU data from Microsofts' datacenter in Ireland, which whilst it is an American company (and thus they are obliged to deliver by law) is illegal under EU and…
Do you think that really matters ?
It's a start. It's better than nothing, unfortunately.
Re: Lavabit Reloaded
#184Earlier quoted context omitted.
The search doesn't happen on the server. The client (e.g. desktop client) indexes the messages and encrypts the index. Then, when another client (e.g. mobile client) wants to search for a message, it downloads the index, searches it, and then pulls down the appropriate message(s).
If an attacker can tell which part of the index was modified, that gives them enough information to decrypt the index and e-mails. Clients would always have to download+upload the full index (which needs to be re-encrypted with a new IV). This is a huge problem - the index can easily be hundreds of MB for a large mailbox.
Technically if a client has a full index version X (in plaintext), it could modify X to get X+1, compute a binary diff between X and (X+1) - encrypt and upload the diff.
Another client on index version X could download the diff, and get index (X+1).
Some desktop client should probably do compaction from time to time.
Re: Lavabit Reloaded
#185Earlier quoted context omitted.
> > Spam checking on content isn't possible > This is probably your best point. It's definitely harder to do well I think it's possible, just slower and more complex (like search) - and would have to occur upon unlocking your inbox.
I don't think Spam checking should be a concern since most spammers aren't going to encrypt their spam.
Might even flag not just plaintext email, but quarantine all mail from unseen senders / public keys. Should make spam filtering much easier.
Re: Lavabit Reloaded
#186Earlier quoted context omitted.
> > Spam checking on content isn't possible > This is probably your best point. It's definitely harder to do well I think it's possible, just slower and more complex (like search) - and would have to occur upon unlocking your inbox.
How often does spam come encrypted with your public key anyways?
Much more often if this is used as a spam measure.
Re: Lavabit Reloaded
#187Earlier quoted context omitted.
Maybe a two-way 'add contact' feature would be useful, like a facebook friend request.
Sure but then it's not standard e-mail any longer.
I remember having a server side system for generating cryptographic email aliases along the lines of:
base64encode(hmac("new-sender@example.com+valid-to+01012018", key))+user@mydomain.com
Truncated to something like fvv544+user@mydomain.com that would only be valid when sent with the from-adress new-sender@example.com (along with some clever magic to avoid email loops! :-)
I think maybe it was authored by ESR (Eric Raymond) in python - but Google only turns up various dkim schemes...
New senders would have their mail held back, and get a "please reply if you are human"-message - a reply (to the "magic" reply-to alias) would release the held mail and whitelist the sender.
A greylist variant of sorts.
Re: Lavabit Reloaded
#188Earlier quoted context omitted.
How often does spam come encrypted with your public key anyways?
Much more often if this is used as a spam measure.
Maybe. Still requires a re-encryption of the symmetric session key for every recipient - effectively proof of work.
"stretching" the equivalent of rsa(session_key, public_key) might be feasible?
Re: Lavabit Reloaded
#189Earlier quoted context omitted.
These are just minor problems. End to end encryption should not be forced upon users, but should be used selectively. You don't want to lose your entire inbox because you wanted to send a few encrypted emails. > The server stores an encrypted index, and the client walks it (requesting parts as needed). It's going to little slower, and a lot more complex but it's doable. How slow would this be with thousands of emails…
> Most email providers don't have retail stores Lots do, though, and the ones that don't often offer customer support over the phone. And anyway, social engineering doesn't only happen in stores or when talking to CS.
Really? Name any of the top 10 email providers that have stores, or a responsive 800 number for email support. I'll give you Apple, but they are the clear outlier. MS, Google, have stores, but not with email support, and questionable phone support at best for any non enterprise product.
Re: Lavabit Reloaded
#190There is no way I would trust lavabit again given it's past...
Would you elaborate?
Can't talk about op, but I got bucked fucked when he shot down with no warning because I had used a nerdshack email to register my primary domain and can't move it do a different email or server.
I am in the process of signing up now, just to restore access and get the hell away from that service. Email is insecure, we know that.