The notation (n, M, d) is used to represent a code with code length n, a total of M codewords, and minimum distance d. One of the major goals of coding theory is to develop codes that strike a balance between having a small n (for fast transmission of messages), a large M (to enable transmission of a wide variety of messages), and a large d (to detect many errors). Describe each of the following using the (n, M, d) notation: (a) C1-(0000, 1100, 0011, 1111} (b) C2={00000, 01101, 10110, 11011} 2

The notation (n, M, d) is used to represent a code with code length n, a total of M codewords, and minimum distance d. One of the major goals of coding theory is to develop codes that strike a balance between having a small n (for fast transmission of messages), a large M (to enable transmission of a wide variety of messages), and a large d (to detect many errors). Describe each of the following using the (n, M, d) notation: (a) C1-(0000, 1100, 0011, 1111} (b) C2={00000, 01101, 10110, 11011} 2

Database System Concepts

7th Edition

ISBN:9780078022159

Author:Abraham Silberschatz Professor, Henry F. Korth, S. Sudarshan

Publisher:Abraham Silberschatz Professor, Henry F. Korth, S. Sudarshan

Chapter1: Introduction

Section: Chapter Questions

Problem 1PE

See similar textbooks

Similar questions

Implement the Hamming Code error detection and correction algorithm for a group message to be transmitted over a network. Hamming code algorithm allows the receiver to detect errors that may have been introduced due to many factors such as noise, interference, and many others. -> Assume the following: 1. The sender message length is 2 bytes. The data transmitted to the user is the 2-byte data in addition to the parity bits. 2. The receiver must be able to detect and correct 1-bit error. Report :In the report you must include an overview of the Hamming code algorithm and you need to show: 1. The detailed calculation of the minimum number of parity bits needed for a message of 2-byte length. 2. Details on how sender generates the parity bits. 3. Details on how thew receiver detects and corrects a 1-bit error. THANKS., PLEASE GIVE DETAILED DESCRIPTION.
Message digests are reasonably fast, but here's a much faster function to compute. Take your message, divide it into 128-bit chunks, and XOR all the chunks together to get a 128-bit result. Finally, do the standard message digest on the result (which is only 128 bits). Is this a good message digest function? Why or why not? You must clearly state your reason, simply giving a yes or no will not earn any credit.
Question ACTIVITY : CODING Suppose the following messages are source encoded given by the table. Message Encoded Bits UP 00 DOWN 01 LEFT 10 RIGHT 11 I. Complete the given table by writing the source encoded message of the following set of directions. Set of Directions Source Encoding LEFT - UP - RIGHT - DOWN 1.) UP - DOWN - UP - RIGHT 2.) DOWN - DOWN - RIGHT - LEFT 3.) UP - DOWN - LEFT - RIGHT 4.) RIGHT - LEFT - RIGHT - UP 5.) II. Decode the set of directions given by the message received. Message Received Decoded Message 10010011 1.) 01010010 2.) 11000110 3.) 01100111 4.) 00101111 5.) III. Complete the given table by writing the channel encoded message by using parity check of adding 1 bit in the message. Message Source Encoding Channel Encoding ALLY 000 1.) ENEMY 011 2.) ATTACK 100 3.) RETREAT 111 4.) SURRENDER 101 5.) IV. Encode the following messages using the given message and the value of r. Source Encoding r Channel…
Assume you are using any correct plaintext padding method, such as those described in lecture, with a 128-bit (16-byte) block cipher. If you are sending a message that is 184 bytes long, how many padding bytes would you need to add? Justify your answer. For the remaining questions, consider a 4-bit block cipher, described in hexadecimal by the following table: Plaintext Ciphertext Plaintext Ciphertext 0 a 8 e 1 c 9 d 2 f a 0 3 6 b 7 4 3 c 5 5 8 d b 6 4 e 9 7 2 f 1 You can think of this as a simple substitution cipher for hexadecimal digits. There is no “key” other than the table itself.
The following message uses a direct mapping of letters to numbers (i.e. A-1, B=2, c-3, etc.).Using the values D=17 and m=21, decrypt the following message:10 15 12 18 1 3 17 14 7 18 14 17 17 9 18 14
Consider an encoding scheme where integer numbers from 1 to 26 are encoded as character 'A' ro 'Z'. for example , integer 1 encodes character 'A' integer 2 encodes character 'B' and so on last till integer number 26 which encodes character 'Z'. Using this encoding scheme, design a system to count all possible decodings for a given digit sequence. For example, for digit sequence "1524" there are three possible decodings. 1, 5, 2, 4 - AEBD 1, 5, 24 - AEX 15, 24 - OX
a. Compute CBC-MAC for a message of 16 bits, “8642” (in Hexa). Assume a block size of 8 bits with an IV=F1 (in hexa). For simplicity, assume the encryption to be a simple XOR of the key with the plaintext. Let the encryption key be B4 (in Hexa). (Hint: Divide the message into blocks of 8 bits each; XOR each block with the previous cipher output; then encrypt this with the key. For the first block, XOR it with IV. Details in pages 325-326 Ch.12 of the textbook) b. Suppose Alice computes the Secret prefix MAC (page 322: secret prefix MAC(x) = h(key || x)) for the message ”AM” (in ASCII) with key “G” (in ASCII) that both Alice and Bob know. The hash function that is used is h(x1x2x3)= g(g(x1 XOR x2) XOR x3 ) where each xi is a character represented as 8 bits, and g(x) is a 8-bit string that is equal to the complement of bits in x. For example, g(10110011) = 01001100. The MAC is 8 bits. (8-bit ASCII representation of the characters is given below.) What is the Secret prefix MAC…
The key to cracking a substitution cipher was first discovered by Arab scholars in the ninth century, but it was not widely known in the West until the fifteenth century. Once frequency analysis of ciphers became widespread, the plain substitution cipher became useless. To fix the problems in the substitution cipher, Blaise de Vigenère invented the strategy of using multiple letter mappings. Rather than using one key for the whole message, Vigenère’s idea was to use a different key for each letter of the message. Using a different key for each letter makes the frequency analysis much more difficult. The key to the Vigenère cipher is the Vigenère square. The rows shown here are simple rotations of the alphabet. Each row in the table shifts the letters of the alphabet one place to the left. When a letter shifts out of the first . The idea is to have the message we want to encode: secretmessage Alongside a word we will use to encrypt: encryptencrypt Plaint text s e c r…
Consider the computer issue. N! equals 1 2 3 N. (a) If N is an n-bit integer, roughly how many bits long is N! (in () form)? (b) Provide a method for calculating N! and examine its execution time.
n alternative to hexadecimal notation for representing bit patterns is dotted decimal notation in which each byte in the pattern is represented by its base ten equivalent. In turn, these byte representations are separated by periods. For example, 12.5 represents the pattern 0000110000000101 (the byte 00001100 is represented by 12, and 00000101 is represented by 5), and the pattern 100010000001000000000111 is represented by 136.16.7. Represent each of the following bit patterns in dotted decimal notation. 0000111100001111 001100110000000010000000 0000101010100000
**Please do C****C IS different from B** a. Compute CBC-MAC for a message of 16 bits, “8642” (in Hexa). Assume a block size of 8 bits with an IV=F1 (in hexa). For simplicity, assume the encryption to be a simple XOR of the key with the plaintext. Let the encryption key be B4 (in Hexa). (Hint: Divide the message into blocks of 8 bits each; XOR each block with the previous cipher output; then encrypt this with the key. For the first block, XOR it with IV. Details in pages 325-326 Ch.12 of the textbook) b. Suppose Alice computes the Secret prefix MAC (page 322: secret prefix MAC(x) = h(key || x)) for the message ”AM” (in ASCII) with key “G” (in ASCII) that both Alice and Bob know. The hash function that is used is h(x1x2x3)= g(g(x1 XOR x2) XOR x3 ) where each xi is a character represented as 8 bits, and g(x) is a 8-bit string that is equal to the complement of bits in x. For example, g(10110011) = 01001100. The MAC is 8 bits. (8-bit ASCII representation of the characters is given…
**Please do A or C** a. Compute CBC-MAC for a message of 16 bits, “8642” (in Hexa). Assume a block size of 8 bits with an IV=F1 (in hexa). For simplicity, assume the encryption to be a simple XOR of the key with the plaintext. Let the encryption key be B4 (in Hexa). (Hint: Divide the message into blocks of 8 bits each; XOR each block with the previous cipher output; then encrypt this with the key. For the first block, XOR it with IV. Details in pages 325-326 Ch.12 of the textbook) b. Suppose Alice computes the Secret prefix MAC (page 322: secret prefix MAC(x) = h(key || x)) for the message ”AM” (in ASCII) with key “G” (in ASCII) that both Alice and Bob know. The hash function that is used is h(x1x2x3)= g(g(x1 XOR x2) XOR x3 ) where each xi is a character represented as 8 bits, and g(x) is a 8-bit string that is equal to the complement of bits in x. For example, g(10110011) = 01001100. The MAC is 8 bits. (8-bit ASCII representation of the characters is given below.) What is the…