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CompTIA Sec +
Sec +
110
Computer Networking
Not Applicable
12/01/2014

Additional Computer Networking Flashcards

 


 

Cards

Term
Substitution Cipher
Definition
Involves replacing units in the plaintext with different ciphertext. Typically rotates or scrambles letters of the alphabet.
Term
Transpostion Cipher
Definition
Units in this cipher stay the same in plaintext and ciphertexr but their order is changed, according to some mechanism.
Term
Mechanical Ciphers
Definition
Any cipher implemented using a machine
Term
Frequency Analysis
Definition
Depends on the fact that some letters and groups of letters appear more frequently in natural language than others. Substitution and transposition are vulnerable to cracking by this analysis. Still used in modern cryptanalysis
Term
Mathematical Ciphers
Definition
based on mathematical algorithms ro perform extremely complex transpositions and substitutions.
Term
Key
Definition
increases security of the encryption process, a message cannot be decrypted without knowledge of the specific key even if the cipher method is known
Term
Keyspace
Definition
range key values available to use with an algorithm, equivalent to 2 to the power of the size of the key.
Term
One-Time-Pad
Definition
is an encryption key itself. consists of exactly the same amount of characters as the plaintext and must be generated by a truly random algorithm. hardest key to break
Term
Quantum Cryptography
Definition
developing field of cryptography and cryptanalysis based on quantum physics.
Term
Secure Hash Algorithm (SHA)
Definition
Developed by the NSA to address weaknesses in MDA.
SHA-1 160-bit digest
SHA-2 using longer digests (up to 512 bits)
Term
Message Digest Algorithm (MDA)
Definition
MD5 128-bit hash
not as secure as SHA-1 but performs better in popular OS
Term
RIPEMD
Definition
RIPEMD-160 offers similar performance and encryption strength to SHA-1
Term
Block Cipher
Definition
Plaintext is divided into equal-size blocks(usually 64- or 128-bit). If there is not enough data in the plaintext, it is padded to the correct size using some string defined by the algorithm
Term
Block Cipher Confusion
Definition
the key should not be derived from the ciphertext. uses substitution units called S-boxes, each S-box operates differently and is determined by the key
Term
Block Cipher Diffusion
Definition
if any one bit of plaintext is changed, half of them should change as a result
Term
Stream Cipher
Definition
each bit or byte of data in the plaintext is encrypted one at a time. this is not predetermined but calculated from the key
Term
Data Encryption Standard (DES/3DES)
Definition
uses 64-bit block cipher and a 56-bit key.
3DES is encrypted 3 times using different keys(typically key1 then key2 and then key1 again)
Term
Advanced Encryption Standard (AES)
Definition
uses 128-bit block cipher and 128-, 192-, or 256-bit key
Term
Rivest Cipher (RC)
Definition
RC4 is a stream cipher uses a variable length key(40 to 2048-bit).
RC5 is a block cipher(32-, 64-, or 128-bit)
Term
International Data Encryption Algorithm (IDEA)
Definition
64-bit block and 128-bit key.
Term
Blowfish
Definition
64-bit block and 32-448 bit key
Term
Twofish
Definition
128-bit block and up to a 256 bit key
Term
CAST
Definition
64-bit block 40-128 bit key
Term
Symmetric Encryption
Definition
uses a single secret key to encrypt and decrypt data.
Term
Asymmetric Encryption
Definition
public key is used to decrypt data while a secret private key is used to encrypt data
Term
Diffie-Hellman
Definition
group 1 (768-bit)
group 2 (1024-bit)
group 5 (1536-bit)
group 2048 (2048-bit)
Term
RSA
Definition
block sizes and key lengths are variable according to the application, with larger keys offering more security.
Term
Elliptic Curve Cryptopgraphy (ECC)
Definition
algorithm for low power devices such as cell phones and PDAs
Term
Digital Signing
Definition
used to prove the identity of the sender of a message
Term
Digital Sealing
Definition
does not protect the contents of a message, provides a layer of confidentiality
Term
Digital Envelopes
Definition
The process of using both a secret-key and public key
Term
Cryptographic Attacks
Definition
made for 2 reasons:
*to decipher encrypted data without authorization
*to impersonate a person or organization by appropriating their digital signature or certificate
Term
Brute Force Attack
Definition
attempts every possible combination in the key space in order to derive a plaintext from a ciphertext. keyspace is determined by the number of bits used
Term
dictionary attack
Definition
guesses the likely value of the plaintext by enumerating values in the dictionary rather than attempting to compute every possible value
Term
rainbow attack
Definition
uses a precomputed lookup table of all possible passwords and their matching hashes
Term
weak key attack
Definition
a key may be generated from a password, if the password is weak, an attacker may be able to guess or crack the password to derive the key
Term
Side channel attack
Definition
by studying physical properties of the cryptographic system, information may be deduced about how it works
Term
steganography
Definition

the container document or file is called the covertext.

obscures the presence of a file within a file, information is usually embedded where you would not expect to find it. 

Term
Single CA
Definition
users trust certificates issued by that CA and no other
disadvantage: restricted to users in a single organization(cannot model different relationships between user groups)
Term
Hierarchial CA
Definition
Single CA(root) issues certificates to a number of intermediate CAs which issue certificates to leaf CAs which issue certificates to users.
advantage: Root can have multiple policies; disadvantage: single point of failure
Term
Mesh CA
Definition
each root CA can issue certificates to other CAs and trust certificates issued by these CAs
advantage: cross-certification; disadvantage: not scalable to a large number of CAs
Term
Bridge CA
Definition
root CAs can establish a trust relationship through an intermediate bridge CA
Term
Web of Trust CA
Definition
users sign one anothers certificates, there is no need for central administration so the system has to be self-policing to weed out malicious users.
Term
Mutual Authentication
Definition
the server authenticates to the client and the client authenticates to the server
Term
phishing
Definition
spoofing a website to imitate a target bank or ecommerce providers secure website, then emailing users of the genuine website informing them that their account must be updated, supplying a disguised link that actually leads to their spoofed site.
Term
vishing
Definition
a phishing attack that is done over a voice channel(telephone or VoIP)
Term
spear phishing/whaling
Definition
a phishing scam where the attacker has some information that makes the target more likely to be fooled by the attack
Term
pharming
Definition
redirecting users from a legitimate website to a malicious one.
Term
virus
Definition
program desgined to replicate and spread amongst computers, usually by "infecting" executable applications or program code
Term
worm
Definition
memory-resident viruses that replicate over network resources
Term
logic bomb
Definition
waits for a preconfigured time or date or system or user event to trigger
Term
fork bomb
Definition
program or script designed to spawn a large number of processes
Term
trojan
Definition
program that pretends to be something else. many function as a backdoor application
Term
spyware
Definition
monitors user activity and sends the information to someone else
Term
adware
Definition
any type of software or browser plug-in that displays advertisments
Term
rootkit
Definition
hard to detect trojan, changes core system files, often at the kernel level, so that GUI browsers and scanning tools no longer reveal their presence, they also contain tools for cleaning system logs
Term
backdoor
Definition
an access method that is installed without the user knowledge, or a hole in software applications from testing or misconfiguration
Term
spam
Definition
unsolicited email meassages
Term
spim/spit
Definition
spam over instant messaging or VoIP
Term
anti-virus software
Definition
software that uses a database of known virus patterns plus heuristic malware identification techniques to try to identif infected files and prevent viruses from spreading
Term
stealth virus
Definition
intercepts commands from anti-virus software and passes the software a clean version of the file; or jump from file-to-file ahead of the virus scanner
Term
modification virus
Definition
polymorphic or metamorphic virus attempts to change itself to avoid detection
Term
armored virus
Definition
the virus code is protected, making it difficult for anti-virus software to analyze it
Term
retrovirus
Definition
seeks to disable the anti-virus software
Term
slow and sparse infectors
Definition
replicate slowly to stay under the radar
Term
OSI model; TCP/IP model
Definition
application = application
presentation = application
session = application
transport = transport
network = internet
data link = link/network interface
physical = link/network interface
Term
link/ network interface layer
Definition
defines the hosts connection to the network. comprised of the hardware and software involved in the interchange of frames between computers
Term
internet layer
Definition
provides addressing and routing functions, uses a number of protocols to ensure the delivery of packets
Term
transport layer
Definition
provides communication between the source and destination computers and breaks application layer information into segments.
Term
application layer
Definition
the layer at which most tcp/ip services protocols are implemented
Term
footprinting and fingerprinting
Definition
an attack that tries to learn the configuration of a network while fingerprinting targets a specific host
Term
spoofing
Definition
an attack where the attacker imitates some sort of resource that the victim thinks is genuine
Term
replay attack
Definition
the attacker captures data packets that contain authentication data and resends the packet to try to re-establish the session
Term
man-in-the-middle attack
Definition
an attack where the attacker sits between two communicating hosts, and transparently monitors, captures, and relays all communication between the hosts
Term
denial of service(DoS)
Definition
an attack that cause a service at a given host to fail or become unavailable to legitimate users
Term
distributed DoS attack
Definition
a DoS attack that is launched from multiple computers, usually done because the attackers resources could be far less than those of the victim
Term
botnet
Definition
a network of zombies
Term
zombie
Definition
a computer that is used to distribute a DoS attack
Term
protocol analyzer
Definition
used to facilitate eavesdropping. 2 main functions: traffic analysis, and packet capture/analysis/transmission
Term
DNS poisoning
Definition
another redirection attack, but it aims to corrupt the records held by the DNS server
Term
What is port 22?
Definition
SSH (encrypted)
Term
What is port 23?
Definition
Telnet (plain text)
Term
What is port 20/21?
Definition
FTP
Term
What is port 3389?
Definition
Firewall port for remote desktop
Term
What is port 25?
Definition
SMTP
Term
What is port 110?
Definition
POP3
Term
What is port 143?
Definition
IMAP
Term
What is port 80?
Definition
HTTP
Term
What is port 443?
Definition
HTTPS
Term
What is port 53?
Definition
DNS
Term
What is port 67?
Definition
DHCP
Term
What is port 115?
Definition
SFTP
Term
What is port 119?
Definition
NNTP
Term
EAP-TLS
Definition
currently considered the strongest type of authentication. protected against sniffing, password-guessing(dictionary), and man-in-the-middle attacks
Term
PEAP
Definition
used in most wireless network authentication products. protected against sniffing, password-guessing(dictionary), and man-in-the-middle attacks. cheaper than EAP-TLS
Term
LEAP
Definition
cisco's proprietary version of EAP. vulnerable to password-guessing(dictionary attacks).
Term
EAP-MD5
Definition
a secure hash of a user password. cannot provide mutual authentication. not suitable for use over insecure networks; vulnerable to man-in-the-middle attacks
Term
confidentiality
Definition
means that certain information should only be known to certain people
Term
integrity
Definition
means that the data is stored and transferred as intended and that any modification is authorized
Term
availability
Definition
means that information is accessible to those authorized to view or modify it
Term
technical control
Definition
implemented by systems
Term
operational control
Definition
implemented by people
Term
management control
Definition
gives oversight of the information system
Term
xmas tree attack
Definition
probes a router by setting flags in a TCP packet all at once
Term
SYN flood
Definition
subverts the TCP handshake process by withholding the client's ACK packet.
Term
bombing
Definition
an attacker generates a large number of HTTP requests or SMTP mail messages designed to overwhelm the server
Term
smurf attack
Definition
the client spoofs the victim's IP address and pings the broadcst address of a third-party network, each host directs its echo responses to the victim server
Term
ARP poisoning
Definition
works by broadcasting unsolicited ARP reply packets, the recieving devices trust this communication and update their MAC:IP address cache table with the spoofed address
Term
DNS spoofing
Definition
compromises the victim's DNS server; replaces valid IP addresses for a trusted website with the attacker's IP address
Term
DNS poisoning
Definition
redirection attack that aims to corrupt the records held by the DNS server itself to redirect traffic for a
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