問題一覧
1
The RSA algorithm is an example of what type of cryptography?
Asymmetric Key
2
Kerberos depends upon what encryption method?
Secret Key cryptograph
3
The DES algorithm is an example of what type of cryptography?
Secret Key
4
Which of the following encryption methods is known to be unbreakable?
One-time pads.
5
What algorithm was DES derived from?
Lucifer.
6
What is a characteristic of using the Electronic Code Book mode of DES encryption?
A given block of plaintext and a given key will always produce the same ciphertext.
7
Where parties do not have a shared secret and large quantities of sensitive information must be passed, the most efficient means of transferring information is to use Hybrid Encryption Methods. What does this mean?
Use of public key encryption to secure a secret key, and message encryption using the secret key.
8
Public Key Infrastructure (PKI) uses asymmetric key encryption between parties. The originator encrypts information using the intended recipient's "public" key in order to get confidentiality of the data being sent. The recipients use their own "private" key to decrypt the information. The "Infrastructure" of this methodology ensures that:
The recipient's identity can be positively verified by the sender.
9
Which of the following statements is true about data encryption as a method of protecting data?
It requires careful key management
10
Which type of algorithm is considered to have the highest strength per bit of key length of any of the asymmetric algorithms?
Elliptic Curve Cryptography (ECC)
11
How many bits is the effective length of the key of the Data Encryption Standard algorithm?
56
12
The primary purpose for using one-way hashing of user passwords within a password file is which of the following?
It prevents an unauthorized person from reading the password
13
Which of the following issues is not addressed by digital signatures?
denial-of-service
14
Brute force attacks against encryption keys have increased in potency because of increased computing power. Which of the following is often considered a good protection against the brute force cryptography attack?
The use of session keys.
15
The Data Encryption Standard (DES) encryption algorithm has which of the following characteristics?
64 bit blocks with a 64 bit total key length
16
PGP uses which of the following to encrypt data?
A symmetric encryption algorithm
17
A public key algorithm that does both encryption and digital signature is which of the following?
RSA
18
Which of the following identifies the encryption algorithm selected by NIST for the new Advanced Encryption
Rijndael
19
Compared to RSA, which of the following is true of Elliptic Curve Cryptography(ECC)?
It is believed to require shorter keys for equivalent security
20
What are the three most important functions that Digital Signatures perform?
Integrity, Authentication and Nonrepudiation
21
Authorization, Detection and Accountability
Authentication Header (AH)
22
Which of the following is a cryptographic protocol and infrastructure developed to send encrypted credit card numbers over the Internet?
Secure Electronic Transaction (SET)
23
Which of the following cryptographic attacks describes when the attacker has a copy of the plaintext and the corresponding ciphertext?
known plaintext
24
Which of the following is NOT a true statement regarding the implementaton of the 3DES modes?
Which of the following is NOT a true statement regarding the implementaton of the 3DES modes?
25
Which of the following ciphers is a subset on which the Vigenere polyalphabetic cipher was based on?
Caesar
26
In a known plaintext attack, the cryptanalyst has knowledge of which of the following?
both the plaintext and the associated ciphertext of several messages
27
What is the length of an MD5 message digest?
128 bits
28
The Secure Hash Algorithm (SHA-1) creates:
a fixed length message digest from a variable length input message
29
The RSA Algorithm uses which mathematical concept as the basis of its encryption?
Two large prime numbers
30
The Clipper Chip utilizes which concept in public key cryptography?
Key Escrow
31
Which of the following are suitable protocols for securing VPN connections at the lower layers of the OSI model?
IPsec and L2TP
32
What is the role of IKE within the IPsec protocol?
peer authentication and key exchange
33
In which phase of Internet Key Exchange (IKE) protocol is peer authentication performed?
Phase 1
34
What is NOT an authentication method within IKE and IPsec?
CHAP
35
What is NOT true with pre shared key authentication within IKE / IPsec protocol?
Needs a Public Key Infrastructure (PKI) to work
36
In a hierarchical PKI the highest CA is regularly called Root CA, it is also referred to by which one of the following term?
Top Level CA
37
What is the primary role of cross certification?
Creating trust between different PKIs
38
What kind of encryption is realized in the S/MIME-standard?
Public key based, hybrid encryption scheme
39
What is the main problem of the renewal of a root CA certificate?
It requires the authentic distribution of the new root CA certificate to all PKI participants
40
Virus scanning and content inspection of SMIME encrypted e-mail without doing any further processing is:
Not possible
41
It is possible only by "brute force" decryption
Distinguished name of the subject
42
What is the primary role of smartcards in a PKI?
Tamper resistant, mobile storage and application of private keys of the users
43
What kind of certificate is used to validate a user identity?
Public key certificate
44
What does the directive of the European Union on Electronic Signatures deal with?
Non repudiation
45
A X.509 public key certificate with the key usage attribute "non repudiation" can be used for which of the following
verifying signed messages
46
Which of the following would best describe certificate path validation?
Verification of the validity of all certificates of the certificate chain to the root certificate
47
Which of the following can best define the "revocation request grace period"?
Time period between the arrival of a revocation request and the publication of the revocation information
48
Which is NOT a suitable method for distributing certificate revocation information?
CA revocation mailing list
49
Which of the following is true about digital certificate?
Electronic credential proving that the person the certificate was issued to is who they claim to be
50
What kind of Encryption technology does SSL utilize?
Hybrid (both Symmetric and Asymmetric)