Internet Commerce - E-Commerce - Lecture Slides, Slides of Fundamentals of E-Commerce

Download Internet Commerce - E-Commerce - Lecture Slides and more Slides Fundamentals of E-Commerce in PDF only on Docsity! E-Commerce C2C Internet Commerce Docsity.com Remarks on First Hour Exam Blue Books • “mass market” = “network effects” • “first-sale rule” = “transfer of copyright” • “digital signatures” = “entity authentication” • signatures and signed documents need not be encrypted Docsity.com eBay Stock Price 0 20 40 60 80 100 120 140 S e p -9 8 O c t- 9 8 N o v -9 8 D e c -9 8 J a n -9 9 F e b -9 9 M a r- 9 9 A p r- 9 9 M a y -9 9 J u n -9 9 J u l- 9 9 A u g -9 9 S e p -9 9 O c t- 9 9 N o v -9 9 D e c -9 9 J a n -0 0 F e b -0 0 M a r- 0 0 A p r- 0 0 M a y -0 0 J u n -0 0 J u l- 0 0 A u g -0 0 S e p -0 0 O c t- 0 0 N o v -0 0 D e c -0 0 J a n -0 1 Time $ Docsity.com eBay Quarterly Revenue 0 20000 40000 60000 80000 100000 120000 140000 160000 Q1 1997 Q2 1997 Q3 1997 Q4 1997 Q1 1998 Q2 1998 Q3 1998 Q4 1998 Q1 1999 Q2 1999 Q3 1999 Q4 1999 Q1 2000 Q2 2000 Q3 2000 Q4 2000 Time $ T h o u s a n d s Docsity.com eBay Business Model • Sellers pay small fee (<$2) per listed item. • eBay takes a cut (~2.5%) of each sale. • Buyers and sellers handle exchange and payment. • eBay has no inventory, no transportation, no costs at all except website operation. Conventional wisdom: Service is technically commoditizable, but strong network effects favor eBay. Docsity.com “E-Cash” Based on Digital Signatures Basic Withdrawal of $A C = Customer B = Bank (A,C) Subtract A from C’s Balance Generate SN = serial number Sig SIGN((A, SN), SKB) ((A, SN), Sig) Docsity.com Basic “E-Cash” Protocols, continued • Spending – Customer gives ((A, SN), Sig) to Merchant – Merchant runs Verify((A, SN), Sig, PKB) • Redemption – Merchant sends ((A, SN), Sig) to its bank – Signature verification and settlement Docsity.com “Blind Signature” Withdrawal Protocol Customer Bank Generate SN Z BlFn(A, SN) Subtract A from C’s Balance BlSig SIGN(Z, SKB) Sig BlFn-1(BlSig) (C, A, Z) (Z, BlSig) Important Properties: • Sig is a valid signature of (A,SN) • C is “unlinkable” to SN during redemption Mathematical idea: “random-self-reducibility” Docsity.com