What is the basis for the difficulty in breaking RSA?
Correct Answer: D
Factoring numbers https://en.wikipedia.org/wiki/RSA_(cryptosystem) RSA (Rivest-Shamir-Adleman) is a public-key cryptosystem that is widely used for secure data transmission. It is also one of the oldest. The acronym RSA comes from the surnames of Ron Rivest, Adi Shamir, and Leonard Adleman, who publicly described the algorithm in 1977. An equivalent system was developed secretly, in 1973 at GCHQ (the British signals intelligence agency), by the English mathematician Clifford Cocks. That system was declassified in 1997. In a public-key cryptosystem, the encryption key is public and distinct from the decryption key, which is kept secret (private). An RSA user creates and publishes a public key based on two large prime numbers, along with an auxiliary value. The prime numbers are kept secret. Messages can be encrypted by anyone, via the public key, but can only be decoded by someone who knows the prime numbers.
Question 42
Which one of the following wireless standards uses the Advanced Encryption Standard (AES) using the Counter Mode-Cipher Block Chaining (CBC)-Message Authentication Code (MAC) Protocol (CCMP)?
Correct Answer: D
WPA2 https://en.wikipedia.org/wiki/Wi-Fi_Protected_Access#WPA2 WPA2 use the Counter Mode-Cipher Block Chaining (CBC)-Message Authentication Code (MAC) Protocol (CCMP).
Question 43
During the process of encryption and decryption, what keys are shared?
Correct Answer: A
Public keys https://en.wikipedia.org/wiki/Public-key_cryptography Public-key cryptography, or asymmetric cryptography, is a cryptographic system that uses pairs of keys: public keys, which may be disseminated widely, and private keys, which are known only to the owner. The generation of such keys depends on cryptographic algorithms based on mathematical problems to produce one-way functions. Effective security only requires keeping the private key private; the public key can be openly distributed without compromising security. In such a system, any person can encrypt a message using the receiver's public key, but that encrypted message can only be decrypted with the receiver's private key. Alice and Bob have two keys of their own - just to be clear, that's four keys total. Each party has their own public key, which they share with the world, and their own private key which they well, which they keep private, of course but, more than that, which they keep as a closely guarded secret. The magic of public key cryptography is that a message encrypted with the public key can only be decrypted with the private key. Alice will encrypt her message with Bob's public key, and even though Eve knows she used Bob's public key, and even though Eve knows Bob's public key herself, she is unable to decrypt the message. Only Bob, using his secret key, can decrypt the message assuming he's kept it secret, of course. Alice and Bob do not need to plan anything ahead of time to communicate securely: they generate their public-private key pairs independently, and happily broadcast their public keys to the world at large. Alice can rest assured that only Bob can decrypt the message she sends because she has encrypted it with his public key.
Question 44
This hash function uses 512-bit blocks and implements preset constants that change after each repetition. Each block is hashed into a 256-bit block through four branches that divides each 512 block into sixteen 32-bit words that are further encrypted and rearranged.
Correct Answer: B
FORK-256 https://en.wikipedia.org/wiki/FORK-256 FORK-256 was introduced at the 2005 NIST Hash workshop and published the following year.[6] FORK-256 uses 512-bit blocks and implements preset constants that change after each repetition. Each block is hashed into a 256-bit block through four branches that divides each 512 block into sixteen 32-bit words that are further encrypted and rearranged. Incorrect answers: SHA1 - (Secure Hash Algorithm 1) is a cryptographic hash function which takes an input and produces a 160-bit (20-byte) hash value known as a message digest - typically rendered as a hexadecimal number, 40 digits long. It was designed by the United States National Security Agency, and is a U.S. Federal Information Processing Standard. RSA - (Rivest-Shamir-Adleman) is a public-key cryptosystem that is widely used for secure data transmission. It is also one of the oldest. The acronym RSA comes from the surnames of Ron Rivest, Adi Shamir, and Leonard Adleman, who publicly described the algorithm in 1977. An equivalent system was developed secretly, in 1973 at GCHQ (the British signals intelligence agency), by the English mathematician Clifford Cocks. That system was declassified in 1997. SHA-256 - SHA-2 (Secure Hash Algorithm 2) is a set of cryptographic hash functions designed by the United States National Security Agency (NSA) and first published in 2001. They are built using the Merkle-Damgard structure, from a one-way compression function itself built using the Davies-Meyer structure from a specialized block cipher. SHA-2 includes significant changes from its predecessor, SHA-1. The SHA-2 family consists of six hash functions with digests (hash values) that are 224, 256, 384 or 512 bits: SHA-224, SHA-256, SHA-384, SHA-512, SHA-512/224, SHA-512/256
Question 45
Which component of IPsec performs protocol-level functions that are required to encrypt and decrypt the packets?
Correct Answer: B
Internet Key Exchange (IKE) https://en.wikipedia.org/wiki/Internet_Key_Exchange Internet Key Exchange (IKE, sometimes IKEv1 or IKEv2, depending on version) is the protocol used to set up a security association (SA) in the IPsec protocol suite. IKE builds upon the Oakley protocol and ISAKMP. IKE uses X.509 certificates for authentication - either pre-shared or distributed using DNS (preferably with DNSSEC) - and a Diffie-Hellman key exchange to set up a shared session secret from which cryptographic keys are derived. Incorrect answers: Oakley - the Oakley Key Determination Protocol is a key-agreement protocol that allows authenticated parties to exchange keying material across an insecure connection using the Diffie-Hellman key exchange algorithm. The protocol was proposed by Hilarie K. Orman in 1998, and formed the basis for the more widely used Internet Key Exchange protocol. IPsec Policy Agent - service provides end-to-end security between clients and servers on TCP/IP networks, manages IPsec policy settings, starts the Internet Key Exchange (IKE), and coordinates IPsec policy settings with the IP security driver. IPsec driver - wrong!
