Domain 5 - Cryptography Flashcards
1
Q
What is the most obvious use for Cryptography?
A
Confidenitaly
2
Q
Hashes and Cryptographic Hashes provide what?
A
Integrity
3
Q
Why isn’t everything encrypted at all times?
A
Availability.
Availability is adversely impacted by cryptography through the introduction of extra risk from loss, distribution, or mismanagement of cryptographic keys.
4
Q
Key Distribution Definition
A
Method of getting a key from where it was generated to where it needs to be used.
5
Q
Key Clustering
A
When different encryption keys generate the same ciphertext from the same plaintext message.
6
Q
Synchoronous
A
Refers to when each encryption or decryption request is performed immediately.
7
Q
Asynchoronous
A
When ENC/DEC requests are processed in a queues.
8
Q
Key benefit of asynchronous cryptography
A
Utilization of hardware devices and multiprocessor systems for cryptographic acceleration.
9
Q
Hash Function
A
One-way mathematical operation that reduces a message or data file into smaller fixed length output, or hash value.
10
Q
Digital Signatures
A
Provide authentication of a sender, and integrity of a sender’s message.
11
Q
How do Digital Signatures work?
A
Sender
- > Message goes into Hash Function
- > Hash Value is encrypted using Sender’s Private Key
Receiver
- > Verifies the digital signature by decryption the hash value using the sender’s public key.
- > Performs same Hash Function
Compares the Hash Functions
12
Q
Asymmetric
A
Term used in cryptography in which two different but mathematically related keys are used where one key is used to encrypt and another is used to decrypt.
Term is used in reference to PKI
13
Q
Digital Certificate
A
Electronic Document that contains the name of an organization or individual, the business address, the digital signature of the CA issuing the certificate, the Certificate’s holder Public Key, a serial number, and an expiration date.
Used to ID the certificate holder when conducting electronic transactions.
14
Q
CA
A
Certificate Authority
Entity trusted by one or more users as an authority in a network that issues, revokes, and manages digital certificates.
15
Q
RA
A
Registration Authority
Performs certificate registration services on behalf of a CA.
The RA, a single-purpose server, is responsible for the accuracy of the information contained in a certificate request.
RA is also expected to perform user validation before issuing a CR.
16
Q
Plaintext/Cleartext
A
Message in its natural format.
17
Q
Ciphertext/Cryptogram
A
Altered form of a plaintext message, so that it’s unreadable for anyone except the intended recipients.
18
Q
Cryptosystem
A
Entire Cryptographic Operation.
Includes: algorithm, key, and key management functions
19
Q
Encryption
A
aka enciphering
Process of converting the message from its plaintext to ciphertext.
20
Q
Decryption
A
Reverse of encryption. Convert ciphertext to plaintext.
21
Q
Cryptovariable
A
AKA Key
Input that controls the operation of the cryptographic algorithm.
Determines the behavior of the algorithm and permits the reliable encryption and decryption of the message.
Both Secret and Public Keys
22
Q
Nonrepudiation
A
Security service by which evidence is maintained so that the sender and the recipient of data cannot deny having participated in the communication.
23
Q
Algorithm
A
Mathematical function that is used in the encryption and decryption process.
24
Q
Cryptanalysis
A
Study of techniques for attempting to defeat cryptographic techniques and, more generally, IS Services
25
Cryptology
Science that deals with hidden, disguised, or encrypted communications.
26
Collision
Occurs when a hash function generates the same output for different inputs.
27
Key Space
Represents the total number of possible values of keys in a cryptographic algorithm or other security measure. such as a password.
28
Work Factor
Time and effort required to break a protective measure.
29
IV
Initialization Vector
Non-secret binary vector used as the initializing input algorithm for the encryption of a plaintext block sequence to increase security by introducing additional cryptographic variance and to synchronize cryptographic equipment.
30
Encoding
Action of changing a message into another format through the use of a code.
Often done by taking a plaintext message and converting it into a format that can be transmitted via radio or some other medium, and is used for message integrity.
31
Decoding
Reverse process of encoding - converting the encoded message back into its plaintext format.
32
Transposition
AKA Permutation
Process of reordering the plaintext to hide the message.
33
Substitution
Process of exchanging one letter or byte for another.
34
SP-Network
Process described by Claude Shannon and used in most block ciphers to increase strength.
Most block ciphers do a series of repeated substitutions and permutations to add confusion and diffusion to the encryption process.
35
Confusion
Provided my mixing (changing) the key values used during the repeated rounds of encryption. When the key is modified for each round, it provides added complexity that the attacker would encounter.
36
Diffusion
Mixing up the location of the plaintext throughout the ciphertext.
Using transposition, the location of the 1st character of the plaintext may change several times during the encryption process.
37
Avalanche Effect
Important Consideration
All Cryptography used to design algorithms where a minor change in either the key or the plaintext will have a significant change in the resulting ciphertext.
Feature of strong-hashing algorithms.
38
Two Primary Methods of Encrypting Data
Stream & Block
Stream is bit-by-bit encryption, most common with streaming applications. WEP uses this.
Block - encrypts in blocks. Used in newer cryptography implements such as AES
39
XOR
Exclusive OR
Very fast mathematical operation used in stream ciphers.
40
Stream Based Cipher
Stream is bit-by-bit encryption, most common with streaming applications. WEP uses this
Relies primary on substitution
More commonly implemented in hardware.
41
Block Ciphers
Operates on blocks or chunks of text.
As plaintext is fed through cryptosystem, it's divided into blocks of a preset size..usually 64b, 128b, 192b, etc
Uses combination of substitution and transposition
More computationally intensive and usually more expensive to implement compared to Stream Based.
More commonly implemented in software.
42
Name the basic Block Cipher Modes
```
ECB - Electronic Code Book
CBC - Cipher Block Chaining
CFB - Cipher Feedback
OFB - Output Feedback
CTR - Counter
```
43
ECB
Electronic Code Book (Block Cipher)
Most Basic
How?
Each block is ciphered independently,
Use?
Any file with non-repeating blocks (less than 64b), such as DES
44
CBC
Cipher Block Chaining (Block Cipher)
How?
Result of a block of encrypting data is fed back into the process to encrypt the next block of data.
Use?
Data at rest
45
CFB
Cipher Feedback (Stream Cipher)
How?
Cipher is used as a keystream generator rather than for confidentiality. Each keystream comes from previous block.
Use?
N/A - Retired due to the delay imposed by encrypting each block of keystream before proceeding.
46
OFB
Output Feedback (Stream Cipher)
How?
Keystream is generated independently of the message.
Use?
N/A - Retired due to Avalanche problems. Was used in Pay-Per-Views apps.
47
CTR
Counter (Stream Cipher)
How?
Uses the formula Encrypt (Base+N) as a keystream generator where Base is a starting 64 bit number and N is a simple, incrementing function.
Use?
Where High Speed or Random Access Encryption is needed. Examples include WPA2 and the Content Scrambling System.
48
IV
Initialization Vector
Arbitrary number that can be used along with a secret key for data encryption. This number, also called a nonce, is employed only one time in any session.
24-bit key used along with a WEP key of 40-bit, making the sum to be 64-bit
USED ONLY ONCE
49
Nonce
Arbitrary number used as the IV.
50
Two main categories of encryption algorithms?
1. Symmetric - AKA Secret Key Encryption uses only 1 key
2. Asymmetric - AKA Public Key Encryption - uses two keys (public and private). Public is used for encryption and private is used for decryption.
51
DES
Data Encryption Standard
First Encryption Standard recommended by NIST.
64-bit key size
64-bit block size
NOT Secure
52
3DES
Triple Data Encryption Standard
192-bit key size
64-bit block size
Slower than other Block Cipher Methods.
53
RC2
Variable Key Size (8-128b)
64-bit Block Cipher
Not Secure because of related-key attack
54
Blowfish
Variable Key Sizes (32 - 448b) Default is 128
64-bit block cipher
Unpatented and Free
55
AES
Advanced Encryption Standard (Block Cipher)
Variable Key Length (128, 192, 256 bits) Default is 256
Encrypts 128-bit data blocks in 10, 12, 14 rounds depending on key size.
Fast, Flexible
56
RC6
Block Cipher derived from RC5
128 -bit Block Size
Key Sizes of 128, 192, 256 bits
57
MD
Message Digest, or just Digest
Hash Value
Small representation of a larger message. Used to ensure authentication, integrity of information, not confidentiality.
58
Main properties of a Hash Function
1. Easy to Compute for any message
2. Infeasible to generate a hashed message
3. infeasible to modify message without modifying hash
4. Infeasible to find 2 different message with same hash.
59
MD 2, 4, & 5
Message Digest Hash Functions used to create message digests for digital signatures.
MD2 - 128-bit message using 128-bit block, through 18 rounds of operation. Still used in certain PKI enviroments.
MD4 - 128-bit message using 512-bit block, through 3 rounds of operations. Popular for File sharing and synchronization applications.
MD5 - 512-bit block generating 128-bit MD as well, over 4 rounds of operation.
60
SHA
Secure Hash Algorithm, V 0, 1, and 2
Collection of hash functions created by US gov't.
SHA-0 is retired
SHA-1 uses a block size of 512b to create a message of 160b through 80 rounds of operation. Susceptible to Bday Attacks.
SHA-2 MD are either 224, 256, 384, 512b in length.
SHA-224 and SHA-256 uses block lengths of 512bits
SHA-384 and SHA-512 uses block lengths of 1024bits
61
HAVAL
Highly Flexible and configurable Hash Function
Hashes can be 128, 160, 192, 224, and 256 bits and use a fixed block size of 128 with 3, 4, or 5 rounds of operation. l
62
RIPEMD-160
Hash Function
Produces 160-bit MD using 512-bit block size.
Not patented
Created in Europe
63
Two ways to attack Hash Algorithms
Brute-Force
| Cyptanalysis
64
Cryptanalysis
Art and Science of defeating cryptographic systems and gaining access to encrypted message even when the keys are unknown.
Responsible for creating Rainbow Tables.
65
Rainbow Tables
Pre-computed tables or lists used in cracking password hashes.
And Open Source version is called Cain and Abel.
66
What fights against Rainbow Tables?
Salting
67
Salted Hashes
Fights against Rainbow Tables
Made of random bits and is an input to the one-way hash function with the target plaintext as the only other input.
Salt is stored in the resulting hash.
68
Primary Function of Salt
To defend against dictionary attacks and against pre-computed rainbow tables.
69
Out of Band
Means using a different channel to transmit the keys. Used in Symmetric Cryptography.
70
Advantages and Disadvantages of Symmetric Cryptography?
Advantages include: Speed, Secure, Cheap
Disadvantages: Key Management Issue, Limitation that algorithm doesn't provide benefits past confidentiality.
71
CCMP
COUNTER MODE WITH CIPHER BLOCK CHAINING MESSAGE AUTHENTICATION CODE
Encryption Protocol based on AES using CTR with CBC-MAC.
Uses 128-b key and 128-b block size
72
MIC
Message Integrity Code
Provides data origin authentication and data integrity for the packet payload data.
73
IDEA
International Data Encryption Algorithm
74
CAST
Feistel-Type Block Cipher
75
SAFER
Secure and Fast Encryption Routine
Patent-Free
Variation of SAFER is used as a block cipher in Bluetooth
76
Blowfish
Symmetrical algorithm.
Very Fast
Key Sizes from 23- 448
S-boxes are stored for later use.
77
TwoFish
Upgrade of Blowfish
78
RC5
Fast and Secure
79
RC4
Stream-Based Cipher
Most widely used stream cipher.
80
How many symmetric keys do you need?
n(n-1) / 2
81
How many asymmetric keys do you need?
2n
82
RSA and 3 primary attacks against it?
Used for secure data transmission. Slow. Uses Prime Numbers
Commonly used to encrypt shared keys for symmetric key cryptography.
1. Brute Force - Trying all possible private keys
2. Mathematical Attacks - factoring the product of two prime numbers
3. Timing Attack - measuring the running time of decryption
83
Diffie-Hellmann
Key Exchange Algorithm
Does NOT provide confidentiality.
Enables two users to exchange or negotiate a secret symmetric key that will be used for encryption.
84
El Gamal
Cryptographic algorithm based on Diffie-Hellmann, but includes confidential and digital signatures services.
85
ECC
Elliptic Curve Cryptography
Used on smart cards, wireless, and other applications.
Provides confidentiality, digital signatures, and message authentication.
86
Message Authentication Code
MAC
AKA cryptographic checksum
Small block of data that is generated using a secret key and then appended to the message. Receiver can decrypt the data and ensure the data has not changed.
Slow when based on DES
87
Characteristics of a Message Authenticate Code
1. Much smaller than the message generating it.
2. Impractical to compute the message that generated it.
3. Impractical to find another message generating same MAC.
88
HMAC
Provides cryptographic strength similar to hashing, except is has additional protection because of a secret key, but is fast.
89
Digital Signature
One way hash of data and then uses private key to encrypt the hash. That has, along with other information is the digital signature.
High quality non-repudiation
90
Non-repudiation
Service that ensures that the sender cannot deny a message was sent and the integrity of the message in intact.
91
How is Non-repudiation accomplished?
Digital Signatures
| PKI
92
What determines for the non-repudiation to be valid?
When the receiver decrypts the digital signature with the sender's public key, it confirms integrity but not ownership of private key.
A CA is used to provide association between private key and sender for non-repudiation.
93
Chosen Plaintext
Cryptanalytic Attack
Attacker knows the algorithm used for encrypting, and may have access to machine used for encrypting.
94
Differential Cryptanalysis
Cryptanalytic Attack
AKA Side Channel Attack
Attacker measures the exact execution times and power required by the crypto device.
95
Linear Cryptanalysis
Cryptanalytic Attack
Known plaintext attack, uses linear approximation to describe the behavior of the block cipher.
96
Algebraic
Cryptanalytic Attack
Release on block ciphers exhibiting a high degree of mathematical structure.
97
How to determine plaintext from hash?
1. Hash each plaintext until a matching hash is found.
2. Hash each plaintext but store each generated hash in a table that can be used as a lookup table so hashes do not need to be generated again.
98
Rainbow Table
Cryptanalytic Attack
Loopup table of sorted hash outputs.
99
Ciphertext-Only Attack
Cryptanalytic Attack
One of the most difficult attacks as the attacker just has some unintelligible data that he suspects may be an important encrypted message.
100
Moore's Law
States that available computing power doubles every 18 months.
101
Known Plaintext
Attacker has access to both the ciphertext and the plaintext versions of the same message.
Goal of this type of attack is to find the link...the cryptographic key that was used to encrypt the message.
102
Chosen Ciphertext
Attacker has access to the decryption device or software and is attempting to defeat the cryptographic protection by decrypting chosen pieces of ciphertext to discover the key.
103
Birthday Attack
Idea that it's easier to find two messages that has to the same message digest than to match a specific message and its specific message digest.
104
Countermeasure used against a Birthday Attack?
Use a hash algorithm with twice the MD length as the desired work factor.
105
Dictionary Attack
Most commonly used against password files.
Encrypts all words in the dictionary and then check whether the resulting hash matches an encrypted password stored in the SAM File.
106
Replay Attack
Attack meant to disrupt and damage processing by the attacker sending repeated files to the host.
107
Factoring Attacks
Aimed at RSA Algorithm, attempts to find the keys through solving the factoring of these numbers.
108
Reverse Engineering
One of the most common.
Act of reverse engineering something to find any vulnerabilities or gain crucial information about the operations of the algorithm.
109
Implementation Attacks
Common and Popular because they are easy and reliable on system elements outside of the algorithm.
1. Side-Channel Analysis - Passive and rely on physical attribute
2. Fault Analysis - Attempts to force system into an error state.
3. Probing Attacks - Attempts to watch the circuity.
110
Safe Harbor
Set of 'Good Faith' Conditions that may temporarily or indefinitely protect the organization from the penalties of a new law or regulation.
111
FISMA
FEDERAL INFORMATION SECURITY MANAGEMENT ACT
Mandates use of specific actions, standards, and requirements for agencies to ensure sensitive information and vital mission services are not disrupted, distorted, or disclosed to improper individuals.
112
PKI
PUBLIC KEY INFRASTRUCTURE
Set of system, software, and communication protocols required to use, manage, and control public key cryptography.
113
PKI's Primary Purposes
1. Publish Public Keys/Certificates
2. Certify that a key is tied to an individual or entity
3. Provide verification of the validity of a public key.
114
How can you be sure that an imposter or attacker isn't using someone else's public key?
1. Setting up a trusted public directory of keys
| 2. Use of Public Key Certificates
115
Standard for Certificate Authority?
X.509
116
Two most important elements in a crypto implementation?
Size of Key
| Secrecy of the Key
117
Techniques to revoke a Certificate
1. CRL (Certificate Revocation List
| 2. OCSP (Online Certificate Status Protocol
118
Kerckhoff's Law
Concept that a cryptographic system should be designed to be secure, even if all its details, except for the key, are publicly known
119
XML
Extensible Markup Language
Flexible data framework that allows applications to communicate on the internet.
Preferred infrastructure of e-commerce.
120
XKMS
XML Key Management Specifications
Defines protocols for distributing and registering public keys
121
Goal of XKMS
Simplicity
122
Two procotols to send an encrypted email?
S/MIME
| PGP
123
Pseudo Randomness
Randomness intrinsically generated by the computer.
124
RNG
Random Number Generators
Special purpose built hardware and software to implement random numbers.
125
Goal of Cryptography
To making the cost of breaking the key worth more than the information being protected.
126
KEK
Key Encrypting Keys
Solution to protect session key with a special purpose long-term use key. This encrypts a symmetric key.
127
Term used in cryptography for when a KEK protects a sesson key?
Key wrapping.
128
Where are keys stored, and what type of keys?
KDC - Key Distribution Center
2 Types of keys, Master Key and Session Key
129
Key Escrow
Process of ensuring a third party maintains a copy of a private key or key needed to decrypt information
130
WOT
Web of Trust
Concept used in PGP, GnuP, and other OpenPGP compatible systems to establish the authenticity of the binding between a public key and its owner.
131
IPSec
Suite of protocols for communicating securely with IP by providing mechanisms for authenticating and encrypting.
Mandatory in IPv6
2 Modes:
Standard: Only authenticates hosts with one another.
Non-standard: Forces users to authenticate.
132
AH
Authentication Header
Used to prove the identity of the sender and ensure that the transmitted data has not been tampered with.
133
How is encryption implemented?
Through the ESP (Encapsulating Security Protocol)
134
SA
Security Associations
Defines the mechanisms that an endpoint will use to communicate with it's partner. Speaks in one-way only.
135
IKE
Internet Key Exchange
Allows communicating partners to prove their identity to each other and establish a secure communication channel.
136
IPSec Extension that is used for highly secure communciations
HAIPE (High Assurance IP Encryptor)
137
What is primarily used to encrypt confidential data sent over an insecure network?
SSL/TLS
Uses both symmetric and asymmetric keys
138
What is the most common protocol for sending digitially signed and encrypted messages?
S/MIME
| Secure/Mutlipurpose Internet Mail Extensions
139
S/MIME
Secure/Multipurpose Internet Mail Extensions
Allows you to encrypt emails and digitally sign them.
Provides Authentication, Integrity, and non-repudiation.
140
ECB encrypts data how?
Electronic Code Book
Uses the same Cipher for each code of block
141
CBC encrypts Data how?
Cipher Block Chaining
Modifying the previous block of ciphertext.
142
What is the best choice for encrypting the entire original data packet in a tunneled mode for an IPSec Solution?
ESP
143
Key Clustering represents a significant failure of an algorithm because...?
2 Different Keys should not generate the same ciphertext from the same plaintext, using the same algorithm.
144
ANSI X9.17
Concerned primarily with the protection and secrecy of keys.
145
How does HMAC work?
Adds secret key value to the input function along with the source message.
146
What are the main types of implementation attacks?
Side-Channel Analysis
Fault Analysis
Probing.
147
Trademarks
Protection of Words and Symbols
148
Copyrights
Protection of creative works
149
Patents
Protection of inventions
150
Trade Secret
Require maintain secrecy but don't expire.
151
Nonce
Randomly generated number added during the CTR Encryption
152
GCM
Galois/Counter Mode
Adds authentication to the the CTR
153
Steps in the Cryptographic Lifecycle
NIST's 5 Phases
1. Initiation
2. Devleop/Acquire
3. Implement/Assess
4. Operations/Maintenance
5. Sunset
154
If Jim wants to send a message to Bob using symmetric cryptography, what key does he use to encrypt the message?
Shared Secret Key
155
Leighton is planning to use a cipher that rearranges the characters in a message. What type of cipher does she need?
Transposition
156
Name the most common types of Symmetric Cryptographies
```
DES
3DES
AES
Blowfish
Twofish
RC4
Steganography
```
157
DES
Symmetric
Block - 64 bit
Key - 56 bit
Insecure
158
3DES
Symmetric
Block - 64 bit
Key - 112 bit
Secure through 2030
159
AES
```
Rijndael algorithm
Symmetric
Block - 128 bit
Key - 128, 192, or 256 bit
All 3 are considered Secure
```
160
Blowfish
```
Public Domain Algorithm
Symmetric
Block - 64 bit
Key - Any key you want through 32 - 448 bit
Not Secure
```
161
Twofish
```
Public Domain Algorithm
Symmetric
Block - 128-bit
Key - 128, 192, 256 bit
Secure
```
162
RC4
Used on WEP and WPA
Used on SSL and TSL
Uses a pseudorandom keystream
No longer secure
Symmetric
Stream Cipher
Key between 40-2048 bit
163
RSA
Assymetric
Keys between 1024 - 4096 b
Considered Secure
164
PGP
Pretty Good Privacy
Uses both Symmetric and Asymmetric Cryptography
Open source is known as GnuPG
165
ECC
Elliptical Curve Cryptography
| Doesn't sure Prime Facorization
166
Leighton is sending me a message via RSA. What key will she encrypt with?
My Public Key
167
What key is used to encrypt with PGP?
Randomly generated key (remember psuedo random)
168
Diffie-Hellman
Algorithm using shared secret.
169
Lowest Diffie-Hellman Group Allowed to be secure
14 with 2048-bit
170
What technology allowed the government access to encrypted communications?
Clipper Chip
171
Key Stretching
a value that was insecure, but has things added to it to add security.
2 Processes - Salting and Hashing
172
Salting
Adds a value to the encryption key to make it more complex.
173
Hashing
Adds time to the verification process by requiring more math.
174
PBKDF2
Key Stretching Technique
Uses salting and hashing.
Should be used 4k times
175
bcrypt
Key stretching with blowfish.
176
3 Key Exchange Trust Models
1. Personal Knowledge
2. WOT
3. PKI
177
WOT Issues
Decentralized Approach makes it difficult to manager
High Barrier to Entry
Requires Technical knowledge
178
PKI
Public Key Infastructure
Depends upon CAs
179
CAs
Certificate Authorities
Trusted 3rd Party organizations who verify the identity of individuals and issues digital certificates
180
Digital Certificates. From Whom and includes what?
From the CA
Contains both the ID information and a copy of the subject's public key.
181
What happens when someone steals a digital certificate?
They are able to encrypt a message using a public key, but can't do anything else as long as the private key remains private.
182
Hash Function
One way functions that transforms variable length input into a unique, fixed-length output.
183
MD5
Hash Function
Produces 128 bit hash
No longer Secure
184
SHA
Created by NIST as Government Standard
SHA-1 (160b) Not secure
SHA-2 (224, 256, 384, 512b) Not secure
SHA -3 (variable hashes set by user)
185
RIPEMD
128, 160, 256, 320b outputs
128 is insecure
Rest are secure
186
HMAC
Has-Based Message Authentication Code
Combines Symmetric Cryptography & Hashing
Provides Authentication & Integrity
187
Hash Functions used in Asymmetric Cryptography? Is so, why?
Yes.
| Used for digital signatures and digital certificates.
188
Digital Signatures?
Use asymmetric cryptography
Achieves Integrity, Authentication, & non-repudiation
189
What key is used on Digital Signatures?
Private key - because we want to be able to be verified by the public key.
190
Do Digital Signatures provide Authentication?
Yes.
191
Do Digital Signatures provide confidentiality?
No.
192
X.509
Digital Certificate Standard
193
How to check for revoked Digital Certificates?
1. OCSF - Live, updated in real time. Used on most browers.
| 2. CRL - Old school list of numbers.
194
Certificate Stapling
Relieves burden on CA.
Extension of OCSP, and reduces the CA's burden.
195
Problem with OCSP?
It places a significant burden on the servers operated by the CA.
196
TLS/SSL
TSL - Encrypts network Communications using cipher suites (other encryption/hashing functions)
Can't be used to encrypt anything!
197
IPSec Components?
ESP - Provides Confidentiality and Integrity for payload packets.
AH - Provides integrity protection for packet headers.
198
ESP vs AH
Both components of IPSec
ESP - Provides Confidentiality & Integrity for packet payloads
AH - Provides Integrity protection for packet headers and payloads.
199
Difference between HTTP and HTTPS
HTTP - Port 80
HTTPS - Port 443
HTTPS adds TLS to web browsing.
200
What is the secure alternative to Telnet?
SSH
201
File Transfer Protocols
FTP - Insecure
FTPS - Adds TLS to FTP
SFTP - Transfers files over SSH
SCP - Provides secure command line transfer vs SSH
202
Difference between FTPS and SFTP?
FTPS - Adds TLS to FTP
| SFTP - Transfers over SSH
203
SCP
Secure Copy Protocol
Provides secure command-line file transfer over SSH
204
TFTP
Trivial File Transfer Protocol
Rarely used and not secure.
205
DKIM
DomainKeys Identified Mail
Provides email authentication by allowing email serves to digitally sign outbound messages.
Must have Public/Private Key Pairs
206
What is the most secure way for web servers and browers to communicate with each other?
TLS
207
Cindy would like to transfer files between two systems over a network. Which protocol performs this action over a secure, encrypted connection?
SCP
208
Another name for Brute Force Attack
Known Cipher Text attack
209
Keyspace
Set of all possible encryption keys usable with an algorithm.
210
Frequency Attack
Detects patterns in the ciphertext
211
Known Plaintext Attack
Attacker has access to an unencrypted message.
212
Chosen Plaintext Attack
Attacker can create an encrypted message of his or her choice.
