1 Chapter 8 Securing Information Systems

Outline Security Threats (External: malware, spoofing/phishing, sniffing, & data theft: Internal: unauthorized data access, theft) Intrusion detections system Firewall Encryption Disaster recovery planning Digital signature and certificate Secure Sockets Layer (SSL) Access control (user authentication) Securing Wireless Networks (WEP) 2

3 Systems Vulnerability Digital data Can be duplicated/changed without being detected Networks Connected to LANs, WANS, & the Internet Anyone from inside/outside the organization can attempt to infiltrate information systems Centralized and integrated data – business benefit, security challenge

Security Threats - External 4 Data theft Defense: Encryption False identity (spoofing/phishing) Malware (virus, worm) Powerouttage, Natural disaster Defense: Plan, facilities Defense: Cautious user Defense: Anti-virus software, Firewall Sniffing Defense: Intrusion detection system

55 Defenses Firewall (blocks Malware) Placed between internal LANs and external networks Need to write/maintain rules that dictate what comes in and what goes out. Part of operating systems Intrusion Detection Systems (blocks data theft) Automatically detects suspicious network traffic at most vulnerable points of network

6 Defenses: Encryption Encryption with Public & Private Key Scrambling of messages to prevent un authorized parties to read them Single key model – Sender and receiver use the same key for encryption and decryption Double key model – Sender and Receiver have their public and private keys: Digital Certificate - public key and a proof of its validity issued by a certificate authority (e.g., VeriSign); licensed annually. Digital Signature – a message encrypted by sender’s private key proving his identity. Both sender and receiver can use it to prove their identity. Encrypt with Recipient’s Public Key Decrypt with Recipient’s Private Key Digital Certificate Digital Signature can be applied

Communications between client and server happen over Secure Socket Layer (SSL) (current name: Transport Layer Security)- Internet protocol for securing data transfer. Supported by operating systems and Web browsers and servers. Negotiations about security, encryption, public key transfers – all happens on SSL/TSL. 7 Defenses: Encryption

88 Security Threats - Internal Theft (stealing data hardware, software) Unauthorized access to data (read, change, delete) Human error (leaving data unprotected, poor & lost passwords, not locking data/hardware/software) Defenses: Security measures Manage data access (system administrators) Training, supervision