Certified Encryption Specialist Practice Questions and Answers Latest

Certified Encryption Specialist Practice Questions and Answers Latest . What type of encryption uses different keys to encrypt and decrypt the message? +Secure +Asymmetric +Private key +Symmetric - Answer Asymmetric Asymmetric cryptography, also known as public key cryptography, uses public and private keys to encrypt and decrypt data. The most widely used asymmetric encryption algorithm is what? +Caesar Cipher +Vigenere +RSA +DES - Answer RSA The RSA encryption algorithm is one of the most widely used public key encryption algorithms that have ever been invented. It was created by the three scientists Ronald Rivest, Adi Shamir, and Leonard Adleman in 1977, and today it is increasingly being used in the network area. Original, unencrypted information is referred to as ____. +text +plaintext +cleantext +ciphertext - Answer Plaintext Plaintext is a term used in cryptography that refers to a message before encryption or after decryption. That is, it is a message in a form that is easily readable by humans. Encryption is the process of obscuring messages to make them unreadable in the absence special knowledge Which of the following is not an asymmetric system? +SSL +DES +PGP +RSA - Answer DES The Data Encryption Standard is a symmetric-key algorithm for the encryption of electronic data. Although now considered insecure, it was highly influential in the advancement of modern cryptography. In order for User A to send User B an encrypted message that only User B can read, User A must encrypt message with which of the following keys? Certified Encryption Specialist Practice Questions and Answers Latest +User B's public key +User B's private key +User A's public key +User A's private key - Answer USER B's Public Key Public key cryptography, or asymmetrical cryptography, is any 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 greatest weakness with symmetric algorithms is _____. +The problem of key exchange +The problem of generating keys +They are slower than asymmetric +They are less secure than asymmetric - Answer The Problem of Key exchange The biggest problem with symmetric key encryption is that you need to have a way to get the key to the party with whom you are sharing data. Which of the following is generally true about block sizes? +Block size is irrelevant to security +Block sizes must be more than 256 bits to be secure +Larger block sizes increase security +Smaller block sizes increase security - Answer Larger Block sizes increase security Larger block sizes do increase security, however at the cost of processing power and encryption time. A _____ is a function that takes a variable-size input m and returns a fixed-size string. +Hash +Symmetric cipher +Feistel +Asymmetric cipher - Answer Hash A hash function is any function that can be used to map data of arbitrary size to data of fixed size. The values returned by a hash function are called hash values, hash codes, digests, or simply hashes. Which of the following is a cryptographic protocol that allows two parties to establish a shared key over an insecure channel? +Elliptic Curve +MD5 +RSA +Diffie-Hellman - Answer Diffie-Hellman Diffie-Hellman key exchange is a method of securely exchanging cryptographic keys over a public channel and was one of the first public-key protocols as originally conceptualized by Ralph Merkle and named after Whitfield Diffie and Martin Hellman. DH is one of the earliest practical examples of public key exchange implemented within the field of cryptography. A _________ is a digital representation of information that identifies you as a relevant entity by a trusted third party? +Ownership stamp +Digest +Digital Signature +Hash - Answer Digital Signature A digital signature is a mathematical scheme for demonstrating the authenticity of digital messages or documents What is the standard used by most digital certificates? +RFC 2298 +OCSP +X.509 +CRL - Answer x.509 In cryptography, X.509 is a standard that defines the format of public key certificates. DES uses keys of what size? +56 bits +192 bits +128 bits +64 bits - Answer 56 bits DES has 2^56 total possible keys Which of the following is not a key size used by AES? +512 bits +128 bits +256 bits +192 bits - Answer 512 bits For AES, NIST selected three members of the Rijndael family, each with a block size of 128 bits, but three different key lengths: 128, 192 and 256 bits. Which of the following was a multi alphabet cipher widely used from the 16th century to the early 20th century? +Caesar +Vigenere +Atbash +Scytale - Answer Vigenere What is now known as the Vigenère cipher was originally described by Giovan Battista Bellaso in his 1553 book La cifra del. Sig. Giovan Battista Bellaso. He built upon the tabula recta of Trithemius, but added a repeating "countersign" (a key) to switch cipher alphabets every letter. Which of the following is a substitution cipher used by ancient Hebrew scholars? +Scytale +Vigenere +Caesar +Atbash - Answer Atbash Atbash is a monoalphabetic substitution cipher originally used to encode the Hebrew alphabet. It can be modified for use with any known writing system with a standard collating order. The technique of moving a given letter a fixed number of spaces to the right or left is called what? +Single substitution +Multi substitution +Bit shifting +Confusion - Answer Single Substitution Single substitution moves one letter a fixed number of spaces to the left or right. Which of the following most accurately defines encryption? +changing a message using complex mathematics +Applying keys to plain text