Securing TCP/IP Flashcards
Block Cipher
An encryption algorithim in which data is encrypted in “chunks” of a certain length at a time.
DES
Data Encryption Standard: A symmetcic-key algorithm developed by the U.S. government in the 1970’s and formerly in use in a variety of TCP/IP applications. DES used a 64-bit block and a 56-bit key. Over time, the 56-bit key made DES susceptible to brute-force attacks.
DES
3DES
IDEA
Blowfish
Stream Cipher
Takes a single bit at a time and encrypts is on-the-fly.
RC4
AES
American Encryption Standard: block cipher that uses a 128-bit block size and 128-, 192-, or 256-bit key size.
Exam Tip: When in doubt on a question about symmetric algorithms, always pick AES. You’ll be right most of the time.
Hash
A cryptographic hash function is a mathematical function that you run on a string of binary digits of any length that results in a value of some fixed length (often called a checksum or a message digest). No matter how long or how short the input, the hash’s message digest will always be the same length (usually around 100 to 500 bits long, depending on the type of hash your use).
CRAM-MD5
Challenge-Response Authentication Mechanism-Message Digest 5
is a tool for server authentication.
PKI
Public Key Infrastructure - The system for creating and distributing digital certificates using sites like Comodo, Symantec, or GoDaddy.
Multifactor Authentication
Using two or more distinctly differednt methods for authentication. Generally, these methods fall into one of six categories, the first five of which you need to remember for the exam.
- something you know (username, passphrase, or PIN)
- something you have (key fob or RFID badge)
- something you are (biometrics)
- somewhere you are (requires you to be in a particular location to authenticate)
- something you do (writing your signature)
ACL
Access Control List: A clearly defined list of permissions that specifies what actions an authenticated user may perform on a shared resource.
There are three types on ACL’s:
- mandatory
- discretionary
- role based
MAC
Mandatory Access Control: A security model in which every resource is assigned a label that defines its security level. If the user lack that security level, they do not get access.
DAC
Discretionary Access Control: authorization method based on the idea that there is an owner of a resource who may at his or her discretion assign access to that resource. DAC is considered much moure flexible that mandatory access control (MAC)
RBAC
Role Based Access Control: The most popular authentication model used in file sharing, defines a user’s access to a resource based on the roles the user plays in the network encironment, This leads to the idea of creation of groups. A group in most networks is nothing more than a name that has clearly defined accesses to different resources. User accournts are placed into various groups.
PPP
Point to Point Protocol: enables two point-to-point devices to connect, authenticate with a user name and password, and negotiate the network protocol the two devices will use.
PPP has two methods of authentication PAP and CHAP
PAP
Passwork Authentication Protocol: simply transmits the user name and password orver the connection in plaintext.
CHAP
Challenge Handshake Authentication Protocol: It has the serving system challenge the remote client, which must provide an encrypted ( hashed ) password.
latest version is MS-CHAPv2: provides the most security over PAP or CHAP
