Attacks on Cryptography, Hashing, Digital Signatures

Question 1

attack using the entire key space (every possible key) and every single combo

can be time consuming

Answer 1

brute force

Question 2

prevents brute force attacks by adding 1-2 seconds to password verification

Answer 2

key stretching

Question 3

Similar to frequency analysis but rather looks for common pairs of letter (TH, HE, ER)

Answer 3

Diagraph Attack

Question 4

Attacker secretly relays and may alter communication between two parties who believe they are directly communicating to each other

Answer 4

man in the middle

Question 5

An attacker takes over a web user’s session ID and masquerades as the authorized user.

Answer 5

Session hijacking

aka TCP hijacking

Question 6

Precompiled lists of plaintext and matching ciphertexts

Answer 6

rainbow tables

Question 7

attacker knows plaintext and ciphertext and by using those can figure out the key

Answer 7

known plaintext attack

Question 8

Similar to known plaintext but attacker also chooses the plaintext then tries to figure out the key

Answer 8

chosen plaintext attack

Question 9

same as chosen plaintext but attacker ‘adapts’ to following rounds dependent on the previous rounds

Answer 9

adaptive chosen plaintext attack

Question 10

A known plain text attack, the intruder knows some parts of the plaintext and ciphertexts which have two or more secret keys for multiple encryptions using the same algorithm

Answer 10

meet-in-the-middle attack

Question 11

attacker knows something about the key

Answer 11

known key attack

Question 12

tries to find difference between related plaintext

Answer 12

differential cryptanalysis

Question 13

attacker has a ton of plaintext and ciphertext pairs and studies the pairs to learn information about the key

Answer 13

linear cryptanalysis

Question 14

differential and linear cryptanalysis combined but the attacker looks for non randomness

Answer 14

differential linear cryptanalysis

Question 15

Using physical data to find flaws in a system. This can be CPU cycles or power consumption etc…

Answer 15

side channel attack

Question 16

Attack where a vulnerability is left from the implementation of an application

Answer 16

Implementation attack

Question 17

When 2 different symmetric keys used on the same plaintext produce the same ciphertext, both can decrypt ciphertext from the other key

Answer 17

key clustering

Question 18

Attacker steals hashed password and gains access to the system by using the stolen hash

Answer 18

pass the hash

Question 19

Similar to pass the hash but used when NTLM is disabled to request a TGT to Kerberos server with user’s hash

Answer 19

Overpass the hash

Question 20

Attacker attempts to collect tickets held in the lsass.exe process the injects the ticket to impersonate the user

Answer 20

pass the ticket

Question 21

Attacker uses NTLM hash to make a TGS ticket. This gives attacker privileges granted to that specific account

Answer 21

silver ticket

Question 22

The attacker gains access to the hash of the Kerberos service account and creates any ticket in Active Directory. The account encrypts all Kerberos tickets with a hash of its own and it never changes.

Answer 22

golden ticket

Question 23

Attackers can guess passwords and usernames by using a script kerbute.py on Linux or Rubeus because Kerberos will report whether the username is valid or not

Answer 23

Kerberos Brute-Force

Question 24

Enables attackers to decrypt tickets and client’s password using offline attacks due to pre-authentication is not enabled

Answer 24

ASREPRoast

Question 25

The attacker collect TGS tickets and decrypts them offline and uses them on accounts without pre-authentication enabled

Answer 25

Kerberoasting

Question 26

The attacker tries to compromise the integrity of crypto devices by introducing external faults (ex: temperature controls)

Answer 26

Fault injection

Question 27

When keys are kept by a 3rd party organization (often law enforcement)

Answer 27

Key Escrow

Question 28

Digital signatures provide integrity and ______-

Answer 28

non repudiation

Question 29

This person issues and revokes certificates

Answer 29

CA (certification authority)

Question 30

Authenticates the certificate holder prior to certificate issuance

Done within organization

Answer 30

ORA (organizational registration authorities)

Question 31

certificates are revoked if a private key is compromised

this list is maintained by the CA

Answer 31

CRL (certificate revocation list)

Question 32

Client/server hybrid to check certificate expiration dates. A dynamic version of CRL

Answer 32

OCSP (online certification status protocol)

Question 33

Chip promoted by the NSA to provide secured voice and data messages but had built in backdoor features. It used Skipjack

Answer 33

Clipper chip

Question 34

Hash function using a key to provide authenticity and integriity

Answer 34

MAC (message authentication code)

Question 35

Combines a shared key with hashing

A preshared key is exchanged

Answer 35

HMAC (hashed message authentication code)

Question 36

Set of protocols that provide a cryptographic layer to IP traffic

Often used for VPNs

Answer 36

IPSEC

Question 37

Part of IPSEC suite that provides authentication and integrity for each packet

protects against replay attacks

Answer 37

AH (authentication header)

Question 38

Part of IPSEC suite that provides confidentiality for each packet

Answer 38

ESP (encapsulation security payload)

Question 39

Part of IPSEC suite. Simplex connection used to negotiate ESP and AH parameters

Answer 39

Security Association (SA)

Question 40

Part of IPSEC suite that manages SA creation process and key exchange mechanics

Answer 40

ISAKMP (internet security and key management protocol)

Question 41

IPSEC mode that encrypts and authenticates the entire package including the headers

Answer 41

Tunnel mode

Question 42

IPSEC mode that encrypts and authenticates the payload

Answer 42

Transport mode

Question 43

IPSEC mode that uses different types of encryption and hashes and selects the fastest and most secure pair

Question 44

Uses a web of trust model to authenticate digital certificates (if you trust me, you trust everyone i trust)

Answer 44

Pretty Good Privacy (PGP)

Question 45

Provides a standard way to format email

Not secure

Answer 45

MIME (multipurpose internet mail extensions)

Question 46

Uses PKI to encrypt and authenticate MIME encoded email

Answer 46

S/MIME (Secure/MIME)