tailieunhanh - Lecture E-commerce and e-business for managers - Chapter 7: Computer and network security

Chapter 7 - Computer and network security. This chapter includes contents: Ancient ciphers to modern cryptosystems; secret-key cryptography; public key cryptography; key agreement protocols; key management; digital signatures; public key infrastructure, certificates and certification authorities; cryptoanalysis; security protocols. | Chapter 7 – Computer and Network Security Outline Introduction Ancient Ciphers to Modern Cryptosystems Secret-key Cryptography Public Key Cryptography Key Agreement Protocols Key Management Digital Signatures Public Key Infrastructure, Certificates and Certification Authorities Cryptoanalysis Security Protocols Secure Sockets Layer (SSL) Secure Electronic Transaction™ (SET™) Security Attacks Network Security Firewalls Kerberos Biometrics Chapter 7 – Computer and Network Security Outline Steganography Introduction Internet security Consumers entering highly confidential information Number of security attacks increasing Four requirements of a secure transaction Privacy – information not read by third party Integrity – information not compromised or altered Authentication – sender and receiver prove identities Non-repudiation – legally prove message was sent and received Availability Computer systems continually accessible Ancient Ciphers to Modern Cryptosystems Cryptography Secures information by encrypting it Transforms data by using a key A string of digits that acts as a password and makes the data incomprehensible to those without it Plaintext – unencrypted data Cipher-text – encrypted data Cipher of cryptosystem – technique for encrypting messages Ciphers Substitution cipher Every occurrence of a given letter is replaced by a different letter Ancient Ciphers to Modern Cryptosystems Transposition cipher Shifts the ordering of letters Modern cryptosystems Digital Key length – length of string used to encrypt and decrypt Secret-key Cryptography Secret-key cryptography Same key to encrypt and decrypt message Sender sends message and key to receiver Problems with secret-key cryptography Key must be transmitted to receiver Different key for every receiver Key distribution centers used to reduce these problems Generates session key and sends it to sender and | Chapter 7 – Computer and Network Security Outline Introduction Ancient Ciphers to Modern Cryptosystems Secret-key Cryptography Public Key Cryptography Key Agreement Protocols Key Management Digital Signatures Public Key Infrastructure, Certificates and Certification Authorities Cryptoanalysis Security Protocols Secure Sockets Layer (SSL) Secure Electronic Transaction™ (SET™) Security Attacks Network Security Firewalls Kerberos Biometrics Chapter 7 – Computer and Network Security Outline Steganography Introduction Internet security Consumers entering highly confidential information Number of security attacks increasing Four requirements of a secure transaction Privacy – information not read by third party Integrity – information not compromised or altered Authentication – sender and receiver prove identities Non-repudiation – legally prove message was sent and received Availability .