Comment by conroy | Hacker News Reader

Comment by conroy | Hacker News Reader

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I've read over the SCIMP protocol. From their white paper, a sample message looks like this:

   <message type="chat"from='velma@silentcircle.com' to='daphne@silentcircle.com'
   id="0FF6CF98-32FE-4EED-9DEF-D66A0E50EA8F"><body/><x xmlns="http://
   silentcircle.com">?
   SCIMP:ewogICAgImRhdGEiOiB7CiAgICAgICAgInNlcSI6IDE1MDcyLAogICAgICAgICJtYWMiOiAiZlp
   YYURlQ1ljVTA9IiwKICAgICAgICAibXNnIjogIkloT051Sm9kK0Fjb09KQ1prZ0xHQXliSmJjbC9WNzhl
   cmMrSFY4K1FHcUJ2cEdlb2RaSWZwNTRKVWluU2g0N0lZTjFORkJOaXBjTVdubWlsMXVtbi9pcG5rVk8rd
   VJZdUJuQjdpZXZEK1pZQzBYV0hHQWQ3WWJtOWRsYkpSd0oyIgogICAgfQp9Cg==.</x></message>

which worries me. Yes, the connection between the server and client will be encrypted, but my message still has metadata that isn't encrypted. I'd just like an answer from Silent Circle / Lavabit.

why dont they address the server and encrypt the user address at the server level, so a network eavesdropper would only see traffic too and from servers but not the particular addresses being addressed. The user puts in an address e.g. yaName@yaDomain.com the sender and receiver address (maName & yaName) are then stripped on sending the D-mail and encrypted with the D-mail servers private key the receiving server (maDomain) then goes through the public private key exchange with the sender (yaDomain) thus securely passing the user address between the two servers without the eavesdropper knowing from what user the D-mail originated and to what user the D-mail was addressed to. This system would become more secure the the greater the number of users on each domain.

To add extra security batch sending by the server would make it even more secure

e.g. every 3min || when unsent messages to domain x > 999 --> send D-mails.

this would add latency and create bandwidth spikes but would negate time based inference attacks.

edit: relevant xkcd; http://xkcd.com/927/

I believe that the SCIMP whitepaper is from 2012. They haven't released their current protocol , and they said they don't want to talk too much about it because there could be changes.

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