Encryption Algorithm scrambles data Last means of defense

Encryption • • Algorithm scrambles data Last means of defense (bypassed all other methods) Protects data stored on a medium or over a communications channel Assurances Provided • Data not modified • Only viewed by intended recipients • Data was not forged

Public Key Encryption • • • Encrypted using two keys • Private User key • Public key Combines user and public key into a key known as the key pair Private key is known only to user Public key is associated with the user and publicly available Most popular public key algorithm is RSA

Secure Shell (SSH) • Is a collection of protocols that provide connection security and data transmitting security. • Steps: Ø Can securely log on to a host. Ø Execute commands on that host. Ø Copy files to and from the host. • Prevents unauthorized access to hose

Key Encryption • • Most popular type of encryption Weaves random string of characters (known as cipher text) Longer cipher text are better Hackers use brute force attack (numerous combinations)

Pretty Good Privacy (PGP) • • • Public key encryption system Verifies the authenticity of an email sender Encrypts email data in transmission Developed to secure email Popular tool for encrypting email messages

Secure Co. Py (SCP) and Secure File Transfer Protocol (SFTP) • • Allows copying of files from on host to antoher securely. Encrypts user names, passwords, and data while transferring. Same just used when a system runs the proprietary version of SSH. Has more steps and security involved than the SCP.

Private Key Encryption • • Uses a single key for both encryption and decryption Also known as asymmetric encryption Most popular type – Data Encryption Standard (DES) • 56 -bit key (original) • Triple DES (3 DES) (current) Advanced Encryption Standard (AES) • 128, 160, 192 or 256 -bit x 3 • More secure and faster • Military security

Secure Socket Layer (SSL) • • Encrypts TCP/IP transmission en route between client and server using public key encryption technologies HTTPS Port 443 rather than 80 Establishes a unique SSL session between the client and browser and determines the how the two will securely exchange data

Internet Protocol Security (IPSec) • • Encrypts data by adding security information to the header of all IP addresses. Phases: Ø Key Management – two nodes agree on the parameters for the keys they will use. Ø Encryption – provides authentication of the IP packet’s data payload.