Section 7: Cryptography Flashcards
(144 cards)
1
Q
Type: Question & Answer
Question: What is the art and science of hiding the meaning of communications from unintended recipients?
A
Answer: Cryptography
2
Q
Type: Question & Answer
Question: What is the study of methods to defeat codes and cyphers?
A
Answer: Cryptoanalysis
3
Q
Type: Question & Answer
Question: Cryptography and Cryptoanalysis together form:
A
Answer: Cryptology
4
Q
Type: Question & Answer
Question: What are keys sometimes referred to as in cryptography?
A
Answer: Cryptovariables
5
Q
Type: Question & Answer
Question: Converting readable data (plaintext) into a scrambled, unreadable format (ciphertext) to ensure information is only accessible to authorised individuals supports the goal of:
A
Answer: Confidentiality
6
Q
Type: Question & Answer
Question: Making sure that information is protected from unauthorised or accidental changes, often using cryptographic functions like Hash, supports the goal of:
A
Answer: Integrity
7
Q
Type: Question & Answer
Question: Verifying the identity of the user, device, or entity during the communication process, often using digital certificates, supports the goal of:
A
Answer: Authentication
8
Q
Type: Question & Answer
Question: What goal of cryptography prevents an entity from denying its involvement in a transaction or activity, ensured by digital signatures?
A
Answer: Non-Repudiation
9
Q
Type: Question & Answer
Question: What are the methods or ways to encrypt and decrypt data, seen as a recipe or set of instructions for the cryptographic process?
A
Answer: Cryptographic Algorithms
10
Q
Type: True/False
Question: The strength and security of an algorithm are determined by its ability to withstand cryptoanalysis and attacks without being fundamentally flawed.
A
Answer: True
11
Q
Type: Question & Answer
Question: What is a set of strings of bits that are used by algorithms to transform data, making the encrypted data unique?
A
Answer: Cryptographic Keys
11
Q
Type: True/False
Question: The security of encrypted data is directly tied to the length and randomness of the key.
A
Answer: True
12
Q
Type: Question & Answer
Question: What type of cypher encrypts data in fixed-size blocks (e.g., AES operates on 128-bit blocks)?
A
Answer: Block Cyphers
13
Q
Type: True/False
Question: Block cyphers are suitable for processing large amounts of data.
A
Answer: True
14
Q
Type: Question & Answer
Question: What type of cypher encrypts data one bit or byte at a time, often used where data arrives in a stream (e.g., RC4)?
A
Answer: Stream Cyphers
14
Q
Type: Question & Answer
Question: What type of cipher involves replacing each letter in the plaintext with another letter shifted a certain number of places up or down the alphabet?
A
Answer: Substitution Cipher (e.g., Caesar Cipher)
15
Q
Type: True/False
Question: RC4 is an example of a stream cypher, but is now seen as insecure.
A
Answer: True
16
Q
Type: Question & Answer
Question: What type of cypher involves arranging the letters of the plaintext according to a certain system, altering their order but not the actual letters?
A
Answer: Transposition Cypher
17
Q
Type: Question & Answer
Question: What technique enhances the security of passwords or other cryptographic keys by transforming a relatively weak key into a stronger, more attack-resistant one?
A
Answer: Key Stretching
18
Q
Type: True/False
Question: Key stretching involves applying a cryptographic hash function to the original key with additional data (salting), making it resource-intensive.
A
Answer: True
19
Q
Type: Question & Answer
Question: What type of cryptographic algorithm uses the same single key for both encryption and decryption?
A
Answer: Symmetric Key Algorithms
20
Q
Type: True/False
Question: Key sharing in symmetric encryption requires the key to be shared and kept secret between parties.
A
Answer: True
20
Q
Type: True/False
Question: Symmetric Key Algorithms are generally faster and more efficient than Asymmetric Key Algorithms.
A
Answer: True
21
Q
Type: Multiple Choice Question (Select ONE answer)
Question: A major challenge with symmetric cryptography, especially in large networks or systems, is:
A) Computational intensity
B) Key management
C) Lack of strong algorithms
D) Inability to encrypt data in transit
A
Answer: B) Key management
22
Type: True/False
Question: In symmetric encryption, if a key is intercepted or leaked during distribution, the security of the encrypted data is compromised.
Answer: True
23
Type: Question & Answer
Question: For N users to communicate securely with each other using symmetric encryption, the number of unique key pairs needed grows significantly, making key management impractical in large systems. This is known as:
Answer: Scalability Issues
24
Type: True/False
Question: Symmetric cryptography does not provide non-repudiation because the same key is used by all parties.
Answer: True
25
Type: Question & Answer
Question: What is an older 64-bit block cypher that uses a 56-bit effective key and is no longer recommended?
Answer: Data Encryption Standard (DES)
26
Type: Question & Answer
Question: What algorithm applies the DES algorithm three times to each 64-bit data block, offering variable key sizes up to 168 bits?
Answer: Triple-DES (3DES)
27
Type: Question & Answer
Question: What 64-bit block cypher was developed to address the short key length of DES, supporting key sizes of 64 or 128 bits?
Answer: International Data Encryption Algorithm (IDEA)
28
Type: True/False
Question: Blowfish is a 64-bit block cypher known for its flexible and large variable key sizes, ranging from 32 bits to 448 bits.
Answer: True
29
Type: True/False
Question: RC4 is a stream cypher widely used in older security protocols like WEP and early SSL/TLS implementations.
Answer: True
30
Type: Question & Answer
Question: What cryptographic system uses pairs of keys (a public key and a private key), where the public key can be disseminated widely and the private key is known only to the owner?
Answer: Asymmetric Encryption (Public-Key Cryptography)
30
Type: Multiple Choice Question (Select ONE answer)
Question: What is the current U.S. government standard for encrypting electronic data, a 128-bit block cypher with variable key sizes (128, 192, or 256 bits)?
A) DES
B) 3DES
C) AES
D) RC4
Answer: C) AES
31
Type: True/False
Question: If a sender encrypts data using the recipient's public key, only the recipient's private key can decrypt it.
Answer: True
32
Type: True/False
Question: In asymmetric encryption, the public key is kept private.
Answer: False (The public key is shared with anyone; the private key is kept secret.)
33
Type: True/False
Question: Asymmetric encryption is more computationally intensive and slower than symmetric encryption.
Answer: True
34
Type: Question & Answer
Question: What foundational asymmetric algorithm relies on the difficulty of factoring large prime numbers for its security, widely used for secure data transmission, digital signatures, and key exchange?
Answer: RSA (Rivest-Shamir-Adleman)
35
Type: Question & Answer
Question: What asymmetric algorithm provides strong security with significantly smaller key sizes compared to RSA, due to its basis in elliptic curve mathematics?
Answer: ECC (Elliptic Curve Cryptography)
36
Type: Multiple Choice Question (Select ONE answer)
Question: What is a method to securely establish a shared secret key between two parties over an insecure public channel, commonly used in SSL/TLS?
A) RSA
B) ECC
C) Diffie-Hellman Key Exchange
D) ElGamal
Answer: C) Diffie-Hellman Key Exchange
37
Type: Question & Answer
Question: What system combines the advantages of both symmetric and asymmetric encryption?
Answer: Hybrid Cryptosystem
38
Type: Question & Answer
Question: In a hybrid system, which type of encryption is used for secure key exchange?
Answer: Asymmetric Encryption
39
Type: Question & Answer
Question: In a hybrid system, which type of encryption is used for encrypting the actual data, providing faster and more efficient encryption?
Answer: Symmetric Encryption
40
Type: True/False
Question: The process of hybrid encryption typically involves creating a symmetric key, encrypting it with the recipient's public key, sending the encrypted symmetric key with the encrypted data, and the recipient using their private key to decrypt the symmetric key.
Answer: True
41
Type: True/False
Question: Hybrid encryption is widely used in modern secure communication protocols like SSL/TLS for web browsing, secure email, VPNs, and cloud storage services.
Answer: True
42
Type: Question & Answer
Question: What cryptographic function converts an input of any length into a fixed-size string of text (a hash value or hash digest) using a mathematical function?
Answer: Hash Function
43
Type: True/False
Question: A good hash function should produce unique and distinct hash values for every different input, and even the smallest change to the input should have a significant impact on the output.
Answer: True
44
Type: Question & Answer
Question: The characteristic that states the same input always produces the same hash value is called:
Answer: Deterministic
45
Type: Question & Answer
Question: The characteristic that states hash functions are usually fast and efficient to compute is called:
Answer: Fast Computation
46
Type: Question & Answer
Question: What characteristic ensures that the hash value should be computationally infeasible to reconstruct the original input (one-way property)?
Answer: Pre-image Resistance
47
Type: Question & Answer
Question: What characteristic means that a minor change in input produces a completely different hash (avalanche effect)?
Answer: Small change leads to a Large difference
48
Type: Question & Answer
Question: What characteristic means it should be extremely unlikely (though not impossible) for two different inputs to produce the same hash value?
Answer: Collision Resistance
49
Type: Question & Answer
Question: What occurs when two different inputs produce the same hash value output, indicating a weakness?
Answer: Collision Hash
50
Type: True/False
Question: MD5 has multiple known collisions.
Answer: True
51
Type: True/False
Question: A Birthday attack is an example of an attack that exploits hash collisions.
Answer: True
52
Type: Multiple Choice Question (Select ONE answer)
Question: Hash algorithms create unique "fingerprints" of data for:
A) Encryption and decryption
B) Digital signatures, certificates, and integrity checks
C) Key exchange
D) Passwordless authentication
Answer: B) Digital signatures, certificates, and integrity checks
53
Type: True/False
Question: SHA-1 has a digest size of 160 bits and is deprecated, meaning it should not be used.
Answer: True
54
Type: True/False
Question: SHA-2 includes versions like SHA-256, SHA-224, SHA-512, and SHA-384.
Answer: True
55
Type: True/False
Question: SHA-256 uses 512-bit blocks for a 256-bit digest.
Answer: True
56
Type: Question & Answer
Question: Which hash algorithm is designed as a "drop-in replacement" for SHA-2, offering similar modes, and is the current standard?
Answer: SHA-3
57
Type: Multiple Choice Question (Select ONE answer)
Question: MD5 (Message Digest 5) has a digest size of 128 bits and is known for:
A) Strong collision resistance
B) Being secure for integrity checks
C) Being prone to collisions and insecure for integrity
D) High computational efficiency
Answer: C) Being prone to collisions and insecure for integrity
58
Type: True/False
Question: RIPEMD (RIPE Message Digest) family algorithms are often used in cryptocurrencies and SSL/TLS.
Answer: True
59
Type: True/False
Question: RIPEMD-128 and RIPEMD-256 are considered insecure and should not be used.
Answer: True
60
Type: Question & Answer
Question: What cryptographic technique validates the authenticity and integrity of a message, software, or digital document?
Answer: Digital Signatures
61
Type: True/False
Question: Digital signatures confirm that the signature was created by the known sender (non-repudiation).
Answer: True
62
Type: Question & Answer
Question: Digital signatures ensure that the message has not been changed while in transit. This is the aspect of:
Answer: Integrity
63
Type: Multiple Choice Question (Select ONE answer)
Question: When creating a digital signature, a hash of the message is encrypted using the sender's:
A) Public key
B) Private key
C) Symmetric key
D) Session key
Answer: B) Private key
64
Type: True/False
Question: To verify a digital signature, the recipient must use the signer's public key to decrypt the signature.
Answer: True
65
Type: True/False
Question: If the decrypted signature matches the newly generated message digest, it confirms that the signature is valid and the message hasn't been altered.
Answer: True
66
Type: Question & Answer
Question: What standard uses the Digital Signature Algorithm (DSA) and was developed by the U.S. National Security Agency (NSA)?
Answer: Digital Signature Standard (DSS)
67
Type: True/False
Question: DSS generates a digital signature for the authentication of electronic documents.
Answer: True
68
Type: True/False
Question: DSS uses SHA2/SHA3 with RSA, DSA, or ECDSA.
Answer: True
69
Type: Question & Answer
Question: What is a framework used to create, manage, distribute, use, store, and revoke digital certificates and manage public-key encryption?
Answer: Public Key Infrastructure (PKI)
70
Type: True/False
Question: The purpose of PKI is to simplify the secure electronic transfer of information for network activities like e-commerce, internet banking, and confidential email.
Answer: True
71
Type: True/False
Question: PKI allows users to encrypt and decrypt data using public and private keys.
Answer: True
72
Type: True/False
Question: PKI provides for the creation and verification of digital signatures, ensuring data authenticity and integrity.
Answer: True
73
Type: Question & Answer
Question: In the functioning of PKI, what entity issues and revokes certificates as needed?
Answer: Certificate Management (CA)
74
Type: Question & Answer
Question: What provides communicating parties with the assurance that they are communicating with the expected party?
Answer: Digital Certificates
75
Type: Multiple Choice Question (Select ONE answer)
Question: Certificates are endorsed copies of an individual's:
A) Private key
B) Symmetric key
C) Public key
D) Hash value
Answer: C) Public key
76
Type: True/False
Question: Digital certificates provide data integrity, identification, authentication, non-repudiation, confidentiality, encryption, and digital signatures.
Answer: True
77
Type: True/False
Question: Computers/machines, individual users, email addresses, and developers (code-signing certificates) are examples of certificate usage.
Answer: True
78
Type: Question & Answer
Question: What electronic documents contain the public key and a digital signature to bind a public key with an identity (person or organisation)?
Answer: Digital Certificates
79
Type: Question & Answer
Question: What trusted entity issues and manages digital certificates, verifying the identity of a certificate applicant before issuing a certificate?
Answer: Certificate Authority (CA)
80
Type: Question & Answer
Question: What entity often acts as the verifier for the CA before a digital certificate is issued to a requestor?
Answer: Registration Authority (RA)
81
Type: Question & Answer
Question: What entity checks if the certificate is still valid?
Answer: Validation Authority (VA)
82
Type: Question & Answer
Question: What is a request sent to a Certificate Authority (CA) to get a digital certificate, containing your public key and details like organisation name and domain name?
Answer: Certificate Signing Request (CSR)
83
Type: True/False
Question: When creating a CSR, you generate a key pair and include your public key in the request.
Answer: True
84
Type: Multiple Choice Question (Select ONE answer)
Question: CSRs are often created in what format?
A) PEM
B) PKCS#10
C) DER
D) PFX
Answer: B) PKCS#10
85
Type: True/False
Question: When submitting a CSR to a CA, the CA performs a validation check on your details.
Answer: True
86
Type: Question & Answer
Question: What is the standard format for digital certificates, used to verify identities and encrypt communications?
Answer: X.509 Digital Certificates
87
Type: True/False
Question: Key information (attributes) in an X.509 certificate includes version number, Subject Name/Common Name (CN), Subject Public Key, and Issuer Name.
Answer: True
88
Type: Question & Answer
Question: What attribute in an X.509 certificate identifies who the certificate is for (e.g., domain name)?
Answer: Subject Name/Common Name (CN)/Distinguished Name (DN)
89
Type: Question & Answer
Question: What attribute in an X.509 certificate identifies who issued the certificate (the CA)?
Answer: Issuer Name
90
Type: Question & Answer
Question: What type of certificate gives an organisation the power to act as a Certificate Authority?
Answer: CA Certificate
91
Type: Question & Answer
Question: What type of certificates are issued to individuals or organisations (not CAs)?
Answer: End Entity Certificates
92
Type: Question & Answer
Question: What type of End Entity Certificate is issued by proving you control the domain (e.g., via email)?
Answer: Domain Validation (DV)
93
Type: Question & Answer
Question: What type of End Entity Certificate provides higher assurance, where the CA thoroughly verifies the business is legitimate?
Answer: Extended Validation (EV)
94
Type: Question & Answer
Question: What type of certificate secures a main domain AND all its subdomains with a single certificate (e.g., *.example.com)?
Answer: Wildcard Certificates
95
Type: True/False
Question: Digital certificates can be created by yourself (self-signed) or issued by a trusted organisation (Third-party CA).
Answer: True
96
Type: True/False
Question: Self-signed certificates are automatically trusted by most browsers and systems.
Answer: False (Self-signed certificates are NOT automatically trusted by others; trust must be set up separately.)
97
Type: True/False
Question: Self-signed certificates are good for test environments and internal networks where users can easily verify authenticity without an external CA.
Answer: True
98
Type: True/False
Question: Third-party (CA-Signed) certificates are automatically trusted by most browsers and systems.
Answer: True
99
Type: Question & Answer
Question: What is the most trusted starting point in a Public Key Infrastructure (PKI) system, where all other certificates in the network derive their trustworthiness?
Answer: Root Certificate Authority (CA) (Root of Trust)
100
Type: True/False
Question: The purpose of certificate verification is to confirm that a certificate is authentic and trustworthy on your device or app.
Answer: True
101
Type: Question & Answer
Question: What technique involves hardcoding a server's SSL/TLS public key into an app/device to prevent Man-in-the-Middle (MITM) attacks?
Answer: Certificate Pinning
102
Type: True/False
Question: To verify a certificate, it must NOT be on a Certificate Revocation List (CRL) or flagged by Online Certificate Status Protocol (OCSP).
Answer: True
103
Type: True/False
Question: A certificate is revoked if it is compromised, issued by mistake, its details change, or its security association changes.
Answer: True
104
Type: Question & Answer
Question: What is a list of revoked certificate serial numbers?
Answer: Certificate Revocation Lists (CRL)
105
Type: Question & Answer
Question: What method allows clients to send a real-time request to the CA's OCSP server to check a certificate's status?
Answer: Online Certificate Status Protocol (OCSP)
106
Type: Question & Answer
Question: What method involves the web server itself checking the certificate's status with the CA and sending a time-stamped validation directly to the client?
Answer: Certificate Stapling
107
Type: Question & Answer
Question: What is a way to embed, or conceal, a message, image, or file within another message, image, or file?
Answer: Steganography
108
Type: Question & Answer
Question: Hiding a message within an image by manipulating pixels or encoding additional data is called:
Answer: Image Steganography
109
Type: Question & Answer
Question: Hiding information within an audio file, or its metadata, is called:
Answer: Audio Steganography
110
Type: Question & Answer
Question: Embedding data within a video file, which can include manipulation of frames, is called:
Answer: Video Steganography
111
Type: Question & Answer
Question: Hiding information within text through formatting, using white spaces, or altering characters is called:
Answer: Text Steganography
112
Type: Question & Answer
Question: What decentralised and distributed ledger technology is known for its role in cryptocurrency, such as Bitcoin?
Answer: Blockchain
113
Type: True/False
Question: In a blockchain, each block contains a cryptographic hash of the previous block, chaining them together to prevent changes.
Answer: True
114
Type: True/False
Question: Blockchain is resistant to central points of failure or control because it is decentralised and maintained over a network of computers.
Answer: True
115
Type: Question & Answer
Question: What technique enhances the security of stored passwords by adding a unique, random string of characters (salt) to each password before it is hashed?
Answer: Salting
116
Type: True/False
Question: In the salting process, the system creates a random unique "salt" for your password, adds it to your actual password, hashes the combined string, and then stores the final hash AND the salt in the database.
Answer: True
117
Type: True/False
Question: When logging in with a salted password, the system gets the salt, adds it to the typed password, hashes the combined string, and then compares it to the stored hash.
Answer: True
118
Type: Question & Answer
Question: What specialised hardware component is designed to secure hardware by integrating cryptographic keys into devices?
Answer: Trusted Platform Module (TPM)
119
Type: True/False
Question: A TPM is built to be tamper-resistant with physical security.
Answer: True
120
Type: Multiple Choice Question (Select ONE answer)
Question: What is the main goal of a TPM?
A) To perform network filtering
B) To protect the system at a hardware level
C) To manage user accounts
D) To encrypt data in transit only
Answer: B) To protect the system at a hardware level
121
Type: True/False
Question: TPMs generate and safely store cryptographic keys (especially private keys) inside the TPM.
Answer: True
122
Type: True/False
Question: TPMs are used in applications like Disk Encryption (storing encryption keys for BitLocker) and Secure Boot/System Integrity (verifying boot process).
Answer: True
123
Type: Question & Answer
Question: What provides a highly secure space where a device with sensitive data can be stored, and cryptographic actions take place, as it's isolated from the main OS and processor?
Answer: Secure Enclave
124
Type: True/False
Question: Hardware Isolation, Limited Access, and Tamper Resistance are key features of a Secure Enclave.
Answer: True
125
Type: Question & Answer
Question: What is the process of disguising confidential or sensitive data to protect it from unauthorised access without making it impossible to understand?
Answer: Data Obfuscation
126
Type: True/False
Question: Data Masking, Encryption, and tokenisation are the three main types of data obfuscation.
Answer: True
127
Type: Question & Answer
Question: What technique involves creating a fake (substitute) version of a dataset, where data values are changed but the original format stays the same, allowing testing/training without risking real user information?
Answer: Data Masking
128
Type: Question & Answer
Question: What process involves substituting sensitive data with non-sensitive equivalents (tokens) that have no explorable meaning or value?
Answer: Tokenisation
129
Type: True/False
Question: In tokenisation, sensitive data (e.g., credit card number) is replaced with a random string of characters called a "token."
Answer: True
130
Type: True/False
Question: In tokenisation, the real sensitive data is stored securely elsewhere, and the token acts as a pointer or reference to that real data.
Answer: True
131
Type: Question & Answer
Question: What process involves securely storing cryptographic keys so that, under certain conditions, a third party can access them, often used for data recovery or law enforcement requests?
Answer: Key Escrow
132
Type: Question & Answer
Question: What physical or cloud computing device provides secure cryptographic processing, key generation, storage, encryption, and decryption services, performing crypto operations inside a tamper-resistant hardware device?
Answer: Hardware Security Module (HSM)
133
Type: True/False
Question: HSMs offer a secure way to manage cryptographic keys through their entire life cycle.
Answer: True
134
Type: True/False
Question: Cloud providers (e.g., AWS) offer HSMs for generating and using cryptographic keys within the cloud environment.
Answer: True
135
Type: Question & Answer
Question: What NIST standard sets requirements for cryptographic modules used in federal IT systems?
Answer: FIPS 140-2
136
Type: Question & Answer
Question: Which FIPS 140-2 Security Level has basic cryptographic functions and production-grade, tamper-evident physical security, used in low-security environments?
Answer: Level 1
136
Type: True/False
Question: The purpose of FIPS 140-2 is to ensure secure handling of cryptographic operations.
Answer: True
137
Type: Question & Answer
Question: Which FIPS 140-2 Security Level adds enhanced physical tamper-evidence and role-based login to Level 1, with visible signs if physical components are accessed, used for moderate security needs?
Answer: Level 2
138
Type: Question & Answer
Question: Which FIPS 140-2 Security Level offers stronger physical protection against accessing sensitive data (CSPs), with hard coverings/enclosures showing tampering and automatic wiping of sensitive data if intrusion is detected?
Answer: Level 3
139
Type: Question & Answer
Question: Which FIPS 140-2 Security Level is the highest, providing robust protection against environmental attacks, complete isolation, strong tamper response, and protection even in extreme environmental conditions?
Answer: Level 4
