[tahoe-dev] [tahoe-lafs] #217: DSA-based mutable files -- small URLs, fast file creation

tahoe-lafs trac at allmydata.org
Tue May 12 14:21:01 UTC 2009


#217: DSA-based mutable files -- small URLs, fast file creation
----------------------------+-----------------------------------------------
 Reporter:  zooko           |           Owner:  zooko     
     Type:  enhancement     |          Status:  assigned  
 Priority:  major           |       Milestone:  eventually
Component:  code-mutable    |         Version:  0.7.0     
 Keywords:  mutable crypto  |   Launchpad_bug:            
----------------------------+-----------------------------------------------

Comment(by swillden):

 Replying to [comment:43 zooko]:
 > I have realized that embedding an ECDSA public key directly into the
 capability doesn't allow for caps to be as short and secure as embedding a
 secure hash of an ECDSA key into the capability. That's because ECDSA keys
 have a crypto strength in bits which is half of their size in bits

 In your semi-private key scheme, they're a little weaker than that,
 because the keyspace is not flat.  This slight weakening is probably
 irrelevant (and can certainly be addressed by adding a few extra bits of
 key size), but it's probably worth thinking about.  Also, it occurs to me
 that perhaps there are other unidentified weaknesses in the semi-private
 key scheme which could be masked by putting hashes of keys in caps, rather
 than keys (though I confess I haven't read/thought enough to understand
 how hashes of keys are useful).

 http://allmydata.org/pipermail/tahoe-dev/2009-February/001106.html

-- 
Ticket URL: <http://allmydata.org/trac/tahoe/ticket/217#comment:44>
tahoe-lafs <http://allmydata.org>
secure decentralized file storage grid


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