telecom Flashcards
Why are switched infrastructures safer environments than routed networks?
A. It is more difficult to sniff traffic since the computers have virtual private connections.
B. They are just as unsafe as nonswitched environments.
C. The data link encryption does not permit wiretapping.
D. Switches are more intelligent than bridges and implement security mechanisms.
A. It is more difficult to sniff traffic since the computers have virtual private connections.
___ attacks allow attackers to gain access to traffic in various VLAN segments, like having the system act as though it is a switch. Attackers can also insert tagging values to manipulate the control of traffic at this data link layer.
VLAN hopping
)___ header protocol provides data integrity, data origin authentication, and protection from replay attacks.
Authentication
___ security payloads protocol provides confidentiality, data origin authentication, and data integrity.
Encapsulating
FACT: Internet Security Association and Key Management Protocol provides a framework for security association creation and key exchange.
yes
Internet Key Exchange provides authenticated keying material for use with the Internet Security Association and Key Management Protocol.
fact
The ______________ is an IETF-defined signaling protocol, widely used for controlling multimedia communication sessions such as voice and video calls over IP.
A. Session Initiation Protocol
B. Real-time Transport Protocol
C. SS7
D. VoIP
A
An effective method to shield networks from unauthenticated DHCP clients is through the use of___________on network switches.
A. DHCP shielding
B. DHCP protection
C. DHCP snooping
D. DHCP caching
C
Which of the following is not one of the stages of the DHCP lease process?
i. Discover
ii. Offer
iii. Request
iv. Acknowledgment
A. All of them
B. None of them
C. i, ii
D. ii, iii
B
Which best describes the IP protocol?
A. A connectionless protocol that deals with dialog establishment, maintenance, and destruction
B. A connectionless protocol that deals with the addressing and routing of packets
C. A connection-oriented protocol that deals with the addressing and routing of packets
D. A connection-oriented protocol that deals with sequencing, error detection, and flow control
B
What takes place at the session layer?
A. Dialog control
B. Routing
C. Packet sequencing
D. Addressing
A
Its used by PPP to validate the id of remote clients. Better security than PAP (password authentication protocol).
CHAP (challenge-handshake authentication protocol).
wirelss LAN auth by CISCO. Features include a dynamic WEP keys and mutal auth bt client and RADIUS server.
LEAP (lightweight extensible authentaction protocol)
is an authentication protocol that uses a pswd. Used by PPP and most all network OS remote servers.
PAP
Define Cryptanalysis
Cryptanalysis is the science of studying and breaking the secrecy of encryption processes, compromising authentication schemes, and reverse-engineering algorithms and keys.
True or False: Cryptosystem is made of at least: sw, protocols, algo, keys.
TRUE
Principle : Plaintxt -> Encrypt -> ciphertxt -> decrypt -> plaintext
fact
In encryption, the key (cryptovariable) is a value that comprises a large sequence of random bits. Is it just any random number of bits crammed together? Not really. An algorithm contains a keyspace, which is a range of values that can be used to construct a key. When the algorithm needs to generate a new key, it uses random values from this keyspace.
fact
One time pad encryption is unbreakable IFF:
The one-time pad encryption scheme is deemed unbreakable only if the following things are true:
1) used only one time.
2) The pad must be as long as the message
3) The pad must be securely distributed and protected at its destination.
4) The pad must be made up of truly random values.
is a method of hiding data in another media type so the very existence of the data is concealed
Steganography
Cipher Terms:
Substitution
Transposition
Runnng Key cipher
concealment cipher
Substitution (shift of alpha)
Transposition (values scrambled or broken up)
Running key cipher Substitution cipher that creates keystream values, commonly from agreed-upon text passages, to be used for encryption purposes. “ Like use of a book.”
Concealment cipher Encryption method that hides a secret message within an open messag. (ex: every 3rd word in a sentence). AKA: null cipher
Symetric Algos
use symm keys aka “secret keys”.
Strengths: Faster than asym sys. Harder to break if key size is lg.
Weakness: Req secure delivery of keys, each pair of users need uniq key, doesn’t provide authenticity or nonrepudiation.
Name a few examples of Sysmetric Algothrims
Examples: of symmetric systems
• Data Encryption Standard (DES) (uses DEA algo)
• 3DES (Triple DES)
• Blowfish
• Twofish
• International Data Encryption Algorithm (IDEA)
• RC4, RC5, and RC6
• Advanced Encryption Standard (AES) (uses Rijndael algo)
• Secure and Fast Encryption Routine (SAFER)
• Serpent
Asymetric Algo
Asymmetric Algos – use “public (known to all) and private (known only to owner) keys”
Strengths
• Better key distribution than symmetric systems.
• Better scalability than symmetric systems
• Can provide authentication and nonrepudiation
Weaknesses
• Works much more slowly than symmetric systems
• Mathematically intensive tasks
