1. 11 , 1995, ,2000, , , 11-2 1

2. , , 11-3 : : 11-4 2 3. B2C: :B2B: : C2C: : 11-5 11-63 4. , , , 11-7 click and bricks Amazon.com, 11-84 5. Yahoo!eBay 11-9 , , 104 11-10 5 6. 11-11 : : 11-12 6 7. :Ex: c a, d b etc.Ex: 11-13 CryptographyEncryptionplaintextciphertextDecryption @#!ZF#@* 11-14 7 8. :Secret keyPublic Key Key : : 11-15 (symmetrickey encryption) 11-16 8 9. - !@#$!^&* !@#$!^&* : 11-17 (public key) (public key)(private key) 11-189 10. (public key) ()() 11-19 RSA Rivest Shamir AdlemanRSAP,Q11-20 10 11. RSA Step1 N = P Q (Npublic keyP, Qprivate key )Step2 e(P - 1) (Q - 1)Step3 (ASCII Code)MCC = Me mod P Q Step1 de d = 1 mod (P-1) (Q - 1)Step2 MM = Cd mod N 11-21 RSA RSA- 1. P=3Q=11; N=PQ=311=33 2. 1(P-1)(Q-1)=(3-1)(11-1)=210=20e=3(e,N)=(3,33) 3. M=19: C=Me mod N=193 mod 33=28 4. d=7 ed (P-1)(Q-1)173201 5. : M=Cd mod N=287 mod 33=19PS: A mode B AB 11-2211 12. RSA factorization challenges e.g., 143 11 x 13Challenge Challenge Prize ($US) Prize ($US)NumberNumber RSA-576$10,000RSA-896$75,000 RSA-640$20,000RSA-1024 $100,000 RSA-704$30,000RSA-1536 $150,000 RSA-768$50,000RSA-2048 $200,000 11-23 US$200,000: RSA-2048251959084756578934940271832400483985714292821262 040320277771378360436620207075955562640185258807 844069182906412495150821892985591491761845028084 891200728449926873928072877767359714183472702618 963750149718246911650776133798590957000973304597 488084284017974291006424586918171951187461215151 726546322822168699875491824224336372590851418654 620435767984233871847744479207399342365848238242 811981638150106748104516603773060562016196762561 338441436038339044149526344321901146575444541784 240209246165157233507787077498171257724679629263 863563732899121548314381678998850404453640235273 81951378636564391212010397122822120720357 11-24 12 13. !@#$!^& *Key A !@#$!^& *Key B Key AKey B 11-25 asdkknrlA (sD34FKJff11-2613 14. - asdkknrlA (sD34FKJff 11-27 RSA (hash) (hash function): (message digest) 11-2814 15. 11-29 (digital envelope): ( ) 11-30 15 16. 11-31 () 11-3216 17. key (Certification Authority) : 11-33 11-3417 18. (PKI) (Public Key Infrastructure) PKI: SSL(Secure Socket Layer) 11-35 11-36 18 19. SET(Secure Electronic Transport) IBM 11-3719