Domain 6

Choose all necessary technology for real WPA. A. 802.1X B. EAP C. TKIP D. WEP

A. 802.1X B. EAP C. TKIP Explanation: WPA involves all of 802.1X, EAP and TKIP

Tom wants to use WPA2 CCMP. In this case, which of these encryption methods is he using? A. AES B. DES C. 3DES D. RC4

A. AES Explanation: AES is the only encryption used in case of WPA2 CCMP. It does not use RC4 or DES or 3DES.

The NIST developed federal government standards beginning in 1991 called digital signature standards. Of the DSS standards RSA and DSA are most commonly used. When two different messages are computed using the same algorithm and the same message digest value results, this is called what?

Collision Explanation: CMAC is a cipher message authentication code. Knapsack algorithm is an outdated no longer used system. One-way hatch takes an arbitrary data set and generates one of fixed length.

Hash functions with longer output are generally considered stronger. Why?

Collisions are less likey Explanation: Even a perfect hash algorithm must have the same output for some pairs of input. These collisions are a way to undermine the security value provided by a hash. The longer the output, the less frequently two inputs are likely to have the same result.

Consider the ciphersuite: SSL_DHE_RSA_WITH_DES_CBC_SHA. The Hash Algorithm here is _______________

SHA Explanation: The correct answer is 'SHA', which can be found at the end of the string. The question describes the workflow of a SHA ciphersuite.

Which of the following is true about SHA? A. Ensures the integrity of the message B. It compromises a three way handshake C. It has the same properties as DES D. All of these

A. Ensures the integrity of the message Explanation: SHA and other hash functions ensure the integrity of a message. SHA produces a 160-bit hash which changes drastically if any of the original data has been modified.

The hash value produced by MD5 is... A. 64 bits B. 128 bits C. 60 bits D. None of these

B. 128 bits Explanation: MD5 is a widely used hash function producing a 128-bit hash value. Although MD5 was initially designed to be used as a cryptographic hash function, like most hash functions, it is neither encryption nor encoding, and can be cracked by brute-force attack and suffers from extensive vulnerabilities.

Which of these is used to issue and revoke certificates in a PKI? A. WPA B. CA C. RADIUS D. Diffie-Hellman

B. CA Explanation: A certificate authority (CA) is the entity which is responsible for authorizing and issuing certificates, along with ensuring certificates are revoked when no longer valid, in a public key infrastructure (PKI).

Which of these is an EAP type: A. PEAP B. EAP-TLS C. EAP-FAST D. All of these

D. All of these Explanation: EAP (Extensible Authentication Protocol) versions include PEAP (Protected EAP), EAP-TLS (EAP Transport Layer Security), EAP-FAST (Flexible Authentication by Secure Tunneling).

Which of the following is the PRIMARY advantage of using symmetric key encryption systems compared to public key systems? A. Fast encryption B. Long keys C. Key management D. Implemented both in hardware and software

A. Fast encryption Explanation: Shared-key systems use symmetric key encryption, which only needs to perform a single, reversible mathematical equation to encrypt or decrypt a file, thus making the process faster.

Which of these does not use symmetric encryption? A. RSA B. Twofish C. AES D. DES

A. RSA Explanation: RSA is an asymmetric encryption algorithm. Twofish, AES and DES are all examples of symmetric encryption algorithms.

What is the effective key size of DES?

56 bits Explanation: DES is the archetypal block cipher, an algorithm that takes a fixed-length string of plaintext bits and transforms it through a series of complicated operations into another cipher text bitstring of the same length. In the case of DES, the block size is 64 bits. DES also uses a key to customize the transformation, so that decryption can supposedly only be performed by those who know the particular key used to encrypt. The key ostensibly consists of 64 bits; however, only 56 of these are actually used by the algorithm. Eight bits are used solely for checking parity, and are thereafter discarded. Hence the effective key length is 56 bits.

Which of the following algorithms is found to be suitable for both digital signature and encryption? A. MD5 B. SHA-1 C. RSA D. AES

C. RSA Explanation: RSA is an algorithm for public-key cryptography. It is the first algorithm known to be suitable for signing as well as encryption, and one of the first great advances in public key cryptography.

Which of the following is true about asymmetric encryption? A. A message encrypted with the public key can be decrypted with the private key B. A message encrypted with the private key can be decrypted with the same key C. A message encrypted with the public key can be decrypted with a shared key D. A message encrypted with a shared key can be decrypted by the same key

A. A message encrypted with the public key can be decrypted with the private key Explanation: Asymmetric encryption involves two keys, private and public. Something encrypted with one can only be decrypted with the other. There is no shared key. A message encrypted with a key can not be decrypted with the same key.

What is the maximum length for MD5 input/output? A. 16 characters B. 23 characters C. 24 characters D. None of these

D. None of these Explanation: MD5 processes an arbitrary-length message into a fixed-length output of 128 bits, typically represented as a sequence of 32 hexadecimal digits.

Which encryption method works on the basis of sender and receivers using different keys for encryption and decryption?

Asymmetric Explanation: The correct answer is asymmetric. It uses different encryption and decryption keys.

WPA2 uses AES for data encryption. What level or strength encryption does it use? A. 128 bit and CRC B. 64 bit and CCMP C. 128 bit CCMP D. 128 bit and TKIP

C. 128 bit CCMP Explanation: Counter Mode with Cipher Block Chaining Message Authentication Code Protocol (CCMP) is an encryption protocol that forms part of the 802.11i standard for wireless local area networks (WLANs), particularly those using WiMax technology. CCMP employs 128-bit keys and a 48-bit initialization vector that minimizes vulnerability to replay attacks.

A Collision problem is seen in which of the following hashing algorithms? A. AES B. SHA-256 C. SHA1 D. Blow fish

C. SHA1 Explanation: SHA1 (and MD5) have Collision problems; SHA2, SHA3 is the one which does not

Which of the following EAP methods is one way authentication only? A. EAP-FAST B. EAP-TTLS C. EAP-TLS D. EAP-MD5

D. EAP-MD5 Explanation: EAP-MD5 was the only IETF Standards Track based EAP method when it was first defined in the original RFC for EAP, RFC 2284. It offers minimal security; the MD5 hash function is vulnerable to dictionary attacks, and does not support key generation, which makes it unsuitable for use with dynamic WEP, or WPA/WPA2 enterprise. EAP-MD5 differs from other EAP methods in that it only provides authentication of the EAP peer to the EAP server but not mutual authentication. By not providing EAP server authentication, this EAP method is vulnerable to man-in-the-middle attacks. EAP-MD5 support was first included in Windows 2000 and deprecated in Windows Vista.

Which feature makes WPA easy to defeat?

PSK Explanation: Improper Preshared Key management(PSK) can make it easy to defeat WPA because passphrases under 20 characters can be easily cracked. WPA was meant to address many flaws of WEP, TKIP provides additional layer of security by adding a wrapper around WEP. WPS is its own Wi-Fi encryption method intended for users that lack the knowledge of security. RC4 is an encryption method but is not used in the four recognized Wi-Fi encryption standards.

How does EAP-FAST provide authentication?

Protected Access Credentials (PAC) Explanation: A PAC is similar to a secure cookie. It is stored locally on the host and act as a proof of a successful authentication.

802.11i was implemented as WPA2. True or False?

True Explanation: 802.11i was created to fix issues in 802.11, and is the standard implemented in WPA2

In symmetric encryption, a secret private key is used to decrypt data, while public key is used to encrypt data. True or False?

False Explanation: Symmetric encryption uses only one key, whereas Asymmetric encyrption uses both private and public keys.

Which encryption method is used when the sender and receiver use an instance of the same key for encryption and decryption purposes?

Symmetric algorithm Explanation: A symmetric algorithm is used where the sender and receiver are using instances of the same key for encryption and decryption purposes. Asymmetric algorithms use different key types both public and private. Block ciphers are a symmetric algorithm that encrypts chunks of data at a time. Diffusion is used in encryption to increase randomness.

WPA2 uses ____ to encrypt the data payload.

AES Explanation: WPA2 uses the Advanced Encryption Standard to encrypt the data payload.

Which of these is an insecure block cipher? A. AES B. RC4 C. ECB D. MD5

C. ECB Explanation: ECB is an implementation of a block cipher which modifies data in such a way that identical plaintext blocks will result in identical ciphertext blocks, making it much easier to identify the encrypted data.

Which of the following EAP variants is supported in current versions of Windows? (Select all that apply.) A. EAP-TLS B. EAP- MD5 C. PEAP D. None of these

A. EAP-TLS C. PEAP Explanation: The Protected Extensible Authentication Protocol, also known as Protected EAP or simply PEAP, is a protocol that encapsulates the Extensible Authentication Protocol (EAP) within an encrypted and authenticated Transport Layer Security (TLS) tunnel. The purpose was to correct deficiencies in EAP; EAP assumed a protected communication channel, such as that provided by physical security, so facilities for protection of the EAP conversation were not provided. EAP-MD5 was the only IETF Standards Track based EAP method when it was first defined in the original RFC for EAP, RFC 2284. It offers minimal security; the MD5 hash function is vulnerable to dictionary attacks, and does not support key generation, which makes it unsuitable for use with dynamic WEP, or WPA/WPA2 enterprise. EAP-MD5 differs from other EAP methods in that it only provides authentication of the EAP peer to the EAP server but not mutual authentication. By not providing EAP server authentication, this EAP method is vulnerable to man-in-the-middle attacks. EAP-MD5 support was first included in Windows 2000 and deprecated in Windows Vista. EAP-Transport Layer Security (EAP-TLS), defined in RFC 5216, is an IETF open standard that uses the Transport Layer Security (TLS) protocol, and is well-supported among wireless vendors. EAP-TLS is the original, standard wireless LAN EAP authentication protocol.

Which of the following describes an asymmetric key algorithm? (select two) A. Requires two separate keys B. Does not require secure exchange of a secret key C. Encryption and decryption is performed using the same key D. Cannot be used to ensure non-repudiation

A. Requires two separate keys B. Does not require secure exchange of a secret key Explanation: An asymmetric key algorithm requires two keys: private (which is never shared) and public (which is openly available), so no key exchange is needed for communication. Messages are encrypted with the recipient's public key and decrypted with the recipient's private key. Private keys are also used in the process of signing messages to ensure non-repudiation.

Which of the following encryption standards does WEP use for confidentiality? A. AES B. RC4 C. 3DES D. RC5

B. RC4 Explanation: The RC4 stream cipher is used with WEP, and vulnerabilities in this implementation amake WEP insecure.

Which encryption standard is used in WEP?

RC4 Explanation: The RC4 algorithm is used in WEP. Although RC4 is for the most part secure, the initialize vector is fairly short and therefore easily predictable. Cracking WEP will take a mere shared key. RC4 is a stream cipher.