Certificates (was Re: Fwd: Είχατε δίκιο ....)

[Patroklos Argyroudis]

On Fri, May 11, 2007 at 02:22:42AM +0300, V13 wrote:
> On Thursday 10 May 2007 21:52, Patroklos Argyroudis wrote:
> > Ti akrivos mou apagoreuei na dimiourgiso ena zeugos klidion kai na to
> > anevaso stous PGP key servers me to onoma tou elkosmas;  Pos kapoios
> > pou anazitei to klidi tou elkosmas tha apofasisei poio einai to sosto;
> 
>   O skopos ton key servers einai na kratane ta keys kai tipote parapano. To na 
> pistopoihseis pos ena public kleidi einai pragmatika aytoy poy se 
> endiaferei[1] , einai ena allo thema. Ayto ginetai eite kykloforontas to se 
> entyph morfh kai antalasontas to xeri-me-xeri, eite meso kapoia selidas klp 
> klp.

Fysika kai mono auto kanoun oi key servers.  To paradeigma pou edosa
fernei stin epifaneia to provlima tou epipedou montelou empistosynis
pou akolouthei to PGP.  Otan theleis na vreis to klidi kapoiou apo ton
opoio den eheis epagkelmatiki karta me to fingerprint, i den ehei
prosopiki selida (tropos pou den empisteuonte oloi), tote hrisimopoieis
tous key servers kai prospatheis na vreis alysida empistosynis apo to
klidi sou sto diko tou.

> [1] Gia tin akribeia, pistopoieis oti aytos poy to eytiakse einai aytos poy se 
> endiaferei. To an exoyn parei alla 150.000 atoma to private kai kai 
> kykloforei kai sto gnutella einai ena allo thema, isos akomi pio diskolo na 
> lythei (CRLs).

To PGP den hrisimopoiei Certificate Revocation Lists (CRLs) gia to
revocation klidion pou ehoun ginei compromised.  Ean kapoios PGP
hristis thelei na kanei revoke to klidi tou (i kapoio certificate pou
ehei ekdosei pros allo hristi) anakoinonei sti prosopiki tou selida (i
se key servers pou parehoun auti ti leitourgia) mia revocation
simiosi.  Apo ekei kai pera einai euthini ton pithanon hriston tou
arhikou klidiou (i pistopoiitikou) na elegksoun ean ehei ginei revoked
i ohi prin to hrisimopoiisoun.  Tora to kata poso autos o eleghos
symvainei sti pragmatikotita apo tous hristes einai allo thema..

Kai ean prokeite gia pistopoiitiko pou o hristis eihe ekdosei paleotera
kai thelei na kanei revoke ehei kalos, ypografei ti revocation simiosi
me to private klidi tou.  Ean omos thelei na kanei revoke to private
klidi tou epeidi pisteuei oti ehei ginei compromised tha prepei na
ypograpsei ti simiosi me ena neo klidi pou tha dimiourgisei.  Poios
kai giati tha empisteutei tin ypografi apo auto to neo klidi;

-- 
Patroklos Argyroudis
http://ntrg.cs.tcd.ie/~argp/