Introduction to Cryptography - D334 Final Exam Questions And Correct Verified Answers. ||ALREADY GRADED A+|| Guaranteed Pass NEWEST VERSION

Introduction to Cryptography - D334 Final Exam Questions And Correct Verified Answers. ||ALREADY GRADED A+|| Guaranteed Pass NEWEST VERSION XOR the following ------------------ - ANSWER asymmetric key-based encryption -typical methods - ANSWER RSA DSA El Gamal Symmetric key-based encryption -Typical Methods - ANSWER RC2- 40 bit key size 64 bit block RC4- (Stream Cipher)- Used in SSL and WEP RC5- (Variable Key size, 32, 64, or 128 bit block size) AES- (128, 192 or 256 bit key size, 128 bit block size) DES- (56 bit key size. 64 bit Block size) 3DES- (112 bit key size, 64 bit block size) Block Encryption - ANSWER RC2(40 bit key size) RC5(Variable block size) IDEA DES 3DES AES (Rijndael) Blowfish Twofish What is the key size for 3DES? - ANSWER 112 bits AES when operating with 10 rounds uses what key size? - ANSWER 128 bits AES when operating with 14 rounds uses what block size? - ANSWER 256 AES when operating with 12 rounds uses what key size? - ANSWER 192 bits Which variation of Elliptic Curve cryptography is used to support symmetric key exchange? - ANSWER ECDH The Paillier cryptosystem supports _____ encryption. - ANSWER homomorphic PKCS #__ is a standard used for password-based encryption. - ANSWER PKCS #5 PKCS #__is used to sign and/or encrypt messages for PKI. - ANSWER PKCS #7 stream encryption - ANSWER RC4 Chacha Rainbow Attack - ANSWER The method of knowing the mapping between the hashed values and the original data Dictionary-type attack - ANSWER a brute force analysis ∉ - ANSWER does not belong to when an object is not in a set ∈ - ANSWER Belongs to when an object is within a set ⊆ - ANSWER subset subset has fewer elements or equal to the set A ∪ B - ANSWER union (objects that belong to set A or set B) | - ANSWER such that A ∩ B - ANSWER Intersection: in both A and B Enigma Machine -Cypher 10 - ANSWER Used a polyalphabetic substitution cipher, which did not repeat within a reasonable time period, along with a secret key. For the cracking of the Enigma cipher, the challenge was thus to determine both the algorithm used and the key. Enigma's main weakness, though, was that none of the plain text letters could be ciphered as itself. Four-square cipher9 - ANSWER Uses four 5 × 5 matrices arranged in a square, are where each matrix contains 25 letters for encoding and decoding operations. One-time pad cypher8 - ANSWER Cypher Code mapping that is only used once. Advantage: it is essentially unbreakable. Disadvantage: it takes lots of work as you would have to generate the pad to be used, each time. Vigenere Cipher 7 - ANSWER Polyalphabetic cipher that involves using a different mapping, based on a keyword, for each character of the cipher. An advantage of this type of cipher is that the same plaintext character is likely to be coded to different mappings, depending on the position of the keyword, making guessing more difficult. Ceasar Cipher6 - ANSWER Mono-alphabetic substitution cipher known as "shift" cipher. Involves plaintext being replaced by a letter some fixed number of positions down the alphabet. i.e., a Caesar Cipher using a shift of +3 would mean a plaintext letter A would result in a ciphertext letter D (a shift of three positions to the right in the alphabet) Morse Code cipher 5 - ANSWER Encoding method, rather than a cipher, that works by translating characters into sequences of dots (.) and dashes (-) Playfair Cipher 4 - ANSWER 5 × 5 matrix containing the alphabet less the letter J. Cipher/decipher process consists of a set of rules outlining use of column and row combinations. BIFID Cipher 3 - ANSWER Makes use of a grid and which maps the letters into numeric values. Rail Code Cipher 2 - ANSWER Employs a method to scramble text by writing it in a sequence across a number of rails. Pig Pen Cipher 1 - ANSWER Mono- alphabetic substitution cipher that makes use of mapping plaintext characters to graphical characters rather than to alphabetic ones. i.e. A=(pick a symbol), vs A=(pick a letter). Disadvantage: once the mapping is known, it is difficult to keep the message secret. Encryption - ANSWER in simplest terms is changing plaintext into ciphertext Decryption - ANSWER The process of converting a ciphertext into plaintext. AESCrypt - ANSWER Encrypt individual files and encrypt full disks with options such as Bitlocker and FileVault Mono-alphabetic - ANSWER c code or substitution is where a single mapping from our alphabet to a cipher alphabet is created. Many early cryptosystems used this. Polyalphabetic - ANSWER refers to the mapping of our alphabet to a number of cipher alphabets. This approach added a bit of complexity to early cryptosystems.