On Thursday 23 April 2009 01:48:46 Matthew Toseland wrote: > It has recently come to our attention that the problem with data persistence > is usually that the top block has fallen out or that the few nodes with the > block are never online at the same time as the person who wants to fetch it. > Hence we need to duplicate the top block. So far there have been two schemes: > 1) Duplicate the top block with SSKs: > SSK,3@<pubkey>,<cryptokey>,<extra>/<filename> would insert e.g. > SSK@<pubkey>,<cryptokey>,<extra>/<filename>-N for a series of N's. > 2) CHKs with extra routing keys: > CHK@<routing key 1>,<routing key 2>,<routing key 3>,<crypto key>,<extra> > > Neither of these schemes is acceptable IMHO. The former allows for an attacker > to insert different content to different keys, and get some info about > targets that way, and it is non-convergent, not allowing for reinserts. The > latter doubles the length of the already way too long CHKs. > > I propose a new key type which is convergent, has URIs shorter than existing > CHKs, and any number of duplicate blocks: the Content Multiplication Key (for > want of a better name, alternatives are welcome). > > DETAILS: > > Insert the splitfile normally, except for the top block. The top block must > fit inside a 1KB SSK payload. > > Hash the content of the top block: > > hash of content: H(data) > > Create a private key: > > privkey = MAKE_PRIVKEY ( H ( H(data) + "0" ) ) > > Create the base crypto key: > > ckey_base = H ( H ( data + "1" ) )
Err, I mean H ( H ( data ) + "1" ) ) > > Create a series of crypto keys: > > ckey_N = H ( ckey_base + "N" ) > > Insert to a series of SSKs: > > SSK@<privkey>,<ckey_N>,<extra> > > Announce the key: > > UMK,N@<H(data)>,<extra>/<filename> > (Where N is the number of copies inserted) > > The filename is ignored. This will make the Frost folk happy. > -------------- next part -------------- A non-text attachment was scrubbed... Name: signature.asc Type: application/pgp-signature Size: 835 bytes Desc: This is a digitally signed message part. URL: <https://emu.freenetproject.org/pipermail/devl/attachments/20090423/17fecba9/attachment.pgp>
