Securing Transactions: Protocols and Politics D. Crocker Brandenberg Consulting D. Crocker Brandenberg Consulting b b b b b b b b

© 1995 D. Crocker, Brandenburg Consulting b b b b b b b b Brandenburg Consulting  Product & service / planning & design  Technical 4 Large-scale systems 4 Internet & interoperability 4 Operations 4 Security 4 Protocols ( , transport, commerce)  Internet development since 1972  Chair, Silicon Valley - Public Access Link

© 1995 D. Crocker, Brandenburg Consulting b b b b b b b b Secure transactions  Doing business on the Internet  Object- vs. Transport- security  Payment protocols  Standards work

© 1995 D. Crocker, Brandenburg Consulting b b b b b b b b Internet for commerce?  Strong pressures emerging 4 Businesses now online 4 Reduced access costs 4 Global “reach”

© 1995 D. Crocker, Brandenburg Consulting b b b b b b b b A global Internet  Scaling 4 A chicken in every pot!  Security 4 Military vs. commercial vs. personal  Management  4 Interconnection  interoperability  4 Sometimes  always

© 1995 D. Crocker, Brandenburg Consulting b b b b b b b b Styles of use  Receiver pull 4 Interactive sessions 4 Individual, foreground refinement  Sender push 4 Messaging 4 Bulk, background distribution (Mark Smith, Intel)

© 1995 D. Crocker, Brandenburg Consulting b b b b b b b b To be on the Internet  Full (core) 4 Permanent, visible, native  Direct (consumer) 4 Native  Client 4 User runs Internet applications  Mediated 4 Provider runs applications for user  Messaging 4 Surprisingly useful

© 1995 D. Crocker, Brandenburg Consulting b b b b b b b b What is business?  R&D 4 Search, browse 4 Test 4 Coordinate  Support 4 Discuss 4 Info push  Marketing 4 Targeted info push 4 Survey  Sales 4 Negotiate 4 Order, bill, pay 4 Deliver

© 1995 D. Crocker, Brandenburg Consulting b b b b b b b b Where to put functions?  Core vs. edges 4 Place it in the core Can’t be used until all of the pieces between users adopt it 4 Place it at the edges Useful as soon as adopted by two, consenting hosts

© 1995 D. Crocker, Brandenburg Consulting b b b b b b b b Where to put security... My object Object Transport Secure My object FTP Web Secure My object Secure My object My object Web Security Web Server MTAMTA MTAMTA Security

© 1995 D. Crocker, Brandenburg Consulting b b b b b b b b Transport security IPSEC IP-level labeling Kerberos (MIT) Third-party service S-KEY (Bellcore) Pairwise login S-HTTP (EIT) Negotiate specifical object wrapper security SSL (Netscape) Client-server transport link STT (Microsoft) (TBD)

© 1995 D. Crocker, Brandenburg Consulting b b b b b b b b Object security  MOSS (was: PEM) 4 MIME Object Security Service - IETF 4 RSA + DES 4 Global, formal key certification hierarchy  PGP 4 Pretty Good Privacy - Phil Zimmerman 4 RSA + IDEA 4 Informal, personal, direct certification  S/MIME 4 Secure MIME - RSA & Consortium

© 1995 D. Crocker, Brandenburg Consulting b b b b b b b b Basic algorithms MsgMsgMsgMsg MsgMsg Msg Hash Msg Hash ++ Ÿ Ÿ + + Key PRIV-ORIG Digital Signatur e Digital + Key DATA Ÿ Ÿ EncryptDataEncryptData Msg Hash Msg Hash + Key DATA + Key PUB-RECIP Key PUB-RECIP IntegrityAuthentication (sign) Privacy (seal) ŸŸ EncryptKeyEncryptKey When do you need each?...not always!

© 1995 D. Crocker, Brandenburg Consulting b b b b b b b b EDI over Internet  Multiple EDI transports already 4 Internet is one more  EDI/MIME, proposed standard 4 Regular EDI objects, encapsulated in MIME 4 Use MIME-based security

© 1995 D. Crocker, Brandenburg Consulting b b b b b b b b Payment system model Buyer Merchant Issuing Bank Acquiring Bank Clearing House 16+4 (M. Rose, FV )

© 1995 D. Crocker, Brandenburg Consulting b b b b b b b b Payment system issues  Transaction category “card not present” 4 For all bankcard approaches for Internet  Issues 4 Knowing buyer/merchant authorized 4 Avoiding third-party interception 4 Interchange, assessment, fees 4 Retrievals, chargebacks, etc. Risk management Risk management

© 1995 D. Crocker, Brandenburg Consulting b b b b b b b b Payment system efforts Commercenet First Virtual Holdings CyberCash Open Market NetMarket Netscape DigiCash

© 1995 D. Crocker, Brandenburg Consulting b b b b b b b b Scheme “Clear” ClearingHouse Buyer Merchant 16+4 in the clear! 16+4 Just trust the net... Easy to capture and replay.

© 1995 D. Crocker, Brandenburg Consulting b b b b b b b b Scheme “ID” ClearingHouse Buyer Merchant 16+4 ID ID 16+4 Still Still trust the net, until the next statement... Easy to capture and replay.

© 1995 D. Crocker, Brandenburg Consulting b b b b b b b b Scheme “ID confirm” ClearingHouse Buyer 16+4 ID ID Confirm ID Merchant Each transaction confirmed. Requires mildly safe user account.

© 1995 D. Crocker, Brandenburg Consulting b b b b b b b b Scheme “Secure link” ClearingHouse Buyer Merchant Encrypted Same a telephone, but encrypt over Internet. Merchant gets number. Is merchant safe??

© 1995 D. Crocker, Brandenburg Consulting b b b b b b b b Scheme “Mediated” ClearingHouse Buyer Merchant Encrypted16+4 Encrypted16+4 Only banks sees data in clear. Limited points of attack.

© 1995 D. Crocker, Brandenburg Consulting b b b b b b b b The standards debate Open IP labeling Session Security S-HTTP (sort of) MOSS Proprietary SSL STT PGP (sort of) S/MIME

© 1995 D. Crocker, Brandenburg Consulting b b b b b b b b Freezing out competition  Non-interoperability mine 4 Do it because it’s mine! 4 Customer lock-in through proprietary extensions  Half-hearted integration 4 Specialized protocols for each and every need

© 1995 D. Crocker, Brandenburg Consulting b b b b b b b b Is there hope?  Vendor initiatives 4 Market lead  Folded into public standards 4 Open access 4 Open enhancement It all depends on market demand. You are the market; start demanding!