?url_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Adc&rft.title=ClaimChain%3A+Improving+the+security+and+privacy+of+in-band+key+distribution+for+messaging&rft.creator=Kulynych%2C+B&rft.creator=Lueks%2C+W&rft.creator=Isaakidis%2C+M&rft.creator=Danezis%2C+G&rft.creator=Troncoso%2C+C&rft.description=The+social+demand+for+email+end-to-end+encryption+is+barely+supported+bymainstream+service+providers.+Autocryptisa+new+community-driven+open+specification+for+e-mail+encryption+that+attempts+to+respond+to+this+demand.+In+Autocrypt+the+encryption+keys+are+attached+directly+to+messages%2C+and+thus+the+encryption+can+be+implemented+by+email+clients+without+any+collaboration+of+the+providers.+The+decentralized+nature+of+this+in-band+key+distribution%2C+however%2C+makes+it+prone+to+man-in-the-middle+attacks+and+can+leak+the+social+graph+of+users.+To+address+this+problem+we+introduce+ClaimChain%2C+a+cryptographic+construction+for+privacy-preserving+authentication+of+public+keys.+Users+store+claims+about+their+identities+and+keys%2C+as+well+as+their+beliefs+about+others%2C+in+ClaimChains.+These+chains+form+authenticated+decentralized+repositories+that+enable+users+to+prove+the+authenticity+of+both+their+keys+and+the+keys+of+their+contacts.+ClaimChains+are+encrypted%2C+and+therefore+protect+the+stored+information%2C+such+as+keys+and+contact+identities%2C+from+prying+eyes.+At+the+same+time%2C+ClaimChain+implements+mechanisms+to+provide+strong+non-equivocation+properties%2C+discouraging+malicious+actors+from+distributing+conflicting+or+inauthentic+claims.+We+implemented+ClaimChain+and+we+show+that+it+offers+reasonable+performance%2C+low+overhead%2C+and+authenticity+guarantees.&rft.publisher=ACM&rft.date=2018-10-15&rft.type=Proceedings+paper&rft.language=eng&rft.source=+++++In%3A++Proceeding+of+Workshop+on+Privacy+in+the+Electronic+Society+2018+(WPES'18).++(pp.+pp.+86-103).++ACM%3A+Toronto%2C+Canada.+(2018)+++++&rft.format=text&rft.identifier=https%3A%2F%2Fdiscovery.ucl.ac.uk%2Fid%2Feprint%2F10068168%2F1%2F1707.06279.pdf&rft.identifier=https%3A%2F%2Fdiscovery.ucl.ac.uk%2Fid%2Feprint%2F10068168%2F&rft.rights=open