[tahoe-dev] Global deduplication of encrypted files

[Francois Deppierraz]

Hi Kenny,

Le 05. 05. 11 23:21, Kenny Taylor a écrit :

> Wuala seems to use the method SpiderOak cautions against.  When a user
> tries to upload a file, the client app encrypts it, hashes it, and asks
> the network if an encrypted file already exists with the same hash.  If
> so, the existing file is linked into the user's account (no upload
> needed!).  It's a neat concept, but it has one big disadvantage:  the
> network can see each user who is sharing a file with a given hash.

By default, Tahoe-LAFS uses a "convergence secret" which is randomly
generated on the client at first run. If you'd like to have file
deduplication between multiple clients (and understand the security
risks), then you'd have to manually set the same convergence secret on
each client.

François