5. What is the biggest advantage of CBC mode of operation O a. It does not need Initialization Vector (IV) O b. A cipher text block depends on all blocks before it O c It does not propagate errors in the cipher text O d. It can encrypt in parallel different parts of the messages
Q: Consider the plaintext PLAINCIPHERTEST, arrange it to 3*5 matrix and rearrange R1 to R3, R2 to R3,…
A: Given plain text is, PLAINCIPHERTEST Arranged in 3*5 matrix Then rearrange R1 to R3, R2 to R3, C1 to…
Q: padding Question 11 Suppose we have a block cipher with block size 8-bytes (64-bits) and we will use…
A: PKCS#5 padding is defined for 8-byte block sizes ECB should not be used if encrypting more than…
Q: In the AES Project, you should change the secret key of the AES by a dynamic key generated by RC4…
A: Creating and managing keys is an essential a part of the cryptographic manner. Symmetric algorithms…
Q: This question concerns block cipher padding. Suppose the block cipher has a block size of 16 bytes.…
A: Answer:-Block ciper has a block size of 16 bytesfinal block of the message is…
Q: here are other modes of block cipher besides the ones (OFB,CFB,CTR). One of these modes is named…
A: Cryptography algorithms fall into two categories, block ciphers and stream ciphers, based on the…
Q: You are to encrypt a ciphertext using the permutation p : {0,1}4 → {0,1}4 defined as p(x) = ~x, ie,…
A: Since you have posted a question with multiple sub-parts, according to the company's policy we will…
Q: This question concerns block cipher padding. Suppose the block cipher has a block size of 20 bytes.…
A: Lets discuss the solution in the next steps
Q: In SMTP, a non-ASCII message of 1000 bytes is encoded with base64. a. How many bytes are in the…
A: Given:- The size if non-ASCII message = 1000 bytes 1 byte = 8 bits The…
Q: 1. Symmetric Encryption and Message Confidentiality: a) Figure 2 shows the Cipher Block Chaining…
A: CBC is designed for chaining, therefore while encryption, if there is one block error, it will…
Q: Most IP datagram reassembly algorithms have a timer to avoid having a lost fragment tie up…
A: IP datagram: The IP datagram is a format of data that can be recognized by IP. IP datagram consists…
Q: Under a modified version of the timestamp protocol, we require that a commit bit be tested to see…
A: Utilizing the commit bit, the read request is created to wait when the transaction that wrote the…
Q: Compare cypher block chaining with cypher feedback mode in terms of the number of encryption…
A: Introduction: The following is the DES (Data Encryption Standard) cypher block chaining mode: Cypher…
Q: 4. We conduct a known plaintext attack on LFSR-based stream cipher. We know that the plaintext was:
A: Given: We conduct a known plaintext attack on LFSR-based stream cipher. We know that the plaintext…
Q: (a) A wants to send a 500 byte packet to D through C. B is supposed to follow the store-and forward…
A: Answer (a): 1 + 10 + 0.4 + 3 = 14.4ms
Q: E system My Dispense Academic Calendar My courses Course dashboard Suppose that a basic key…
A: one of the main attack, public key encryption is vulnerable is Brute-force attack. Brute force…
Q: A [answer] cipher is typically implemented by performing a AND mathematical operation at least two…
A: Stream cipher is an encryption technique which uses symmetric key that encrypts and decrypts the…
Q: This question concerns block cipher modes. We will use a simple affine cipher, which can be…
A: Programming is instructing a computer to do something for you with the help of a programming…
Q: Compare cypher block chaining versus cypher feedback mode in terms of the number of encryption…
A: Introduction: The DES cypher block chaining mode is as follows: Cypher mode is a kind of…
Q: This question concerns block cipher modes. We will use a simple affine cipher, which can be…
A: Code and output given below:
Q: This question concerns block cipher modes. We will use a simple affine cipher, which can be…
A: def ofb(string): xs = list() ys = list() ss = list() for character in string:…
Q: What is the biggest advantage of CBC mode of operation O It does not need Initialization Vector (IV)…
A: Advantage of CBC mode is in step 2.
Q: Stream cipher works using the xor operation. Assume the first ten bits of plaintext are…
A: Stream cipher is a strong cryptographic method for securing data. It is simple in execution, only a…
Q: Given a plaintext in HEX P1=AE1C, the encrypted cipher text is C1=87D2 with key K through stream…
A:
Q: Q2) Suppose that ciphertext C3 is damaged in transmission. Which plaintext blocks become…
A: Solution 1)
Q: This question concerns block cipher padding. Suppose the block cipher has block size of 18 bytes. A…
A: The Answer is
Q: Using a block encoding scheme with encoding matrix ?=⌊3 5⌋ 23 a) Encrypt block (M Q) by listing…
A: Answer: I have given answered in the handwritten format
Q: b) Suppose a bank organization MyBank has designed a system in which a symmetric session key is…
A: According to the guidelines we are allowed to answer only the first question. - The question wants…
Q: (a) Write the equation representing encryption and decryption operation for this new mode. (b)…
A: Answer is given below .
Q: 2. Encrypt the word SHIELD using an alphabetic Caesar shift cipher that starts with a shift of 8 (A…
A:
Q: This question concerns block cipher padding. Suppose the block cipher has a block size of 16 bytes.…
A: ANSWER:-
Q: With the ECB mode, if there is an error in a block of the transmitted ciphertext, only the…
A: Answer:
Q: In modern encryption, plaintext is encoded in binary form. Each bit in a bit stream is encrypted…
A: Introduction: A stream cypher joins plaintext digits with a pseudorandom figure digit stream…
Q: Prior to the introduction of IEEE 802.11i, the security scheme for IEEE 802.11 was Wired Equivalent…
A: Given :- Prior to the introduction of IEEE 802.11i, the security scheme for IEEE 802.11 was Wired…
Q: 5. What is the biggest advantage of CBC mode of operation a. A cipher text block depends on all…
A: CBC mode of operation provides message dependence for generating ciphertext and makes the system…
Q: We demand that a commit bit be evaluated to verify whether a read request needs wait under an…
A: Introduction: To wait till the transaction that wrote the data element has been committed, the read…
Q: Modes of operation such as CFB and CBC require the use of an initial variable (IV), which must be…
A: Hey there, I am writing the required solution of the above stated question.Please do find the…
Q: Suppose you have a block cipher with block length of 32 bytes (256-bits). Suppose you want to…
A: A Ciphertext is encrypted text transformed from plaintext using encryption algorithm. It can't be…
Q: Comparing CBC mode to OFB mode, only in OFB mode... A. each block is encrypted separately B. an…
A: GIVEN: Comparing CBC mode to OFB mode, only in OFB mode... A. each block is encrypted separately…
Q: To provide nonrepudiation we can: O a. encrypt the message with receiver public key O b. append our…
A: We have to discuss to provide nonrepudiation we can used :
Q: Would it be possible to execute encryption functions in parallel on CBC mode with multiple blocks of…
A: In CBC(Cipher Block Chaining) encryption the input block to each and every forward cipher operation…
Q: Draw a diagram showing the PDU messages exchange of writing a file of 782 bytes from TP server.…
A: We need to answer -
Q: Exam2: Problem 6 Previous Problem Problem List Next Problem Consider the following two methods for…
A: The answer provided below has been developed in a clear step by step manner. First Step | All Steps…
Q: 2) The RC4 stream cipher, used in the WEP encryption scheme, relies on an initialization vector…
A: Given that, The RC4 stream cipher, used in The WEP encryption scheme, relies on an initialization…
Q: What is the biggest advantage of CBC mode of operation a. It does not need Initialization Vector…
A: Please find the answer below :
Step by step
Solved in 2 steps
- Assume that you have a suitable source of randomness which can produce at least 264264 random bits before it repeats. What is the easiest way to turn this into a stream cipher suitable for encrypting long streams of plaintext?There are other modes of block cipher besides the ones (OFB,CFB,CTR). One of these modes is named Plaintext Block Chaining (PBC) Mode. On the encryption side, the following is executed to obtain the nth ciphertext: Cn := Ek(Mn)XOR Mn-1. Suppose that we need to encrypt M1; : : : ;M5 using the PBC mode. Show the explicit formulas to obtain C1; : : : ;C5. What do you need to use for M0? Also, show the steps on the decryption side to obtain M1; : : : ;M5.You are to encrypt a ciphertext using the permutation p : {0,1}4 → {0,1}4 defined as p(x) = ~x, ie, toggle each bit (0 to 1 and 1 to 0). If you need an IV use 1010. If you need a nonce use 01. If the mode uses padding to handle arbitrary plaintext lengths, add 10* padding. If you need a counter, begin at 1. Encrypt the ciphertext 1110 1110 111 using ECB mode. Write four bits per box, with the final box possibly having fewer bits. Encrypt the ciphertext 1110 1110 111 using CBC mode. Write four bits per box, with the final box possibly having fewer bits. Encrypt the ciphertext 1110 1110 111 using CTR mode. Write four bits per box, with the final box possibly having fewer bits. Encrypt the ciphertext 1110 1110 111 using OFB mode. Write four bits per box, with the final box possibly having fewer bits.
- In the AES Project, you should change the secret key of the AES by a dynamic key generated by RC4 after every 1024 bits, remember you should encrypt an image of 512*512*3 bytes, moreover, the used mode of operation should be CBC mode, Finally, use the attached figure to find the Number of cycles per byte and the encryption throughput?Comparing CBC mode to OFB mode, only in OFB mode... A. each block is encrypted separately B. an initialization vector is utilized C. each ciphertext block depends on the previous ciphertext block D. a key stream is utilizedYou have an originating plain text message (in hexadecimal): 41 72 61 62 Use your Student ID number to obtain a 10-bit key as follows: Key (in decimal) = (ID mod 1024) +1.You have to manually cipher the first block of the following plain text message (first 8 bits). The encrypting process will be done using Simplified DES (S-DES). you must explain all steps in details [mandatory: write down all the calculations].
- 1.Give the decryption of the following messages that have been encrypted with the key 4551. You should get readable messages. a. RTYAWJHVVJ b. WYFUMXYJGX c. VTRFS_NMPJEJPQNOSNX 2.Say you obtain a ciphertext of an English sentence encrypted with an unknown key using the same four-digit shift scheme as problems 8 and 9. For a brute-force attack, what is the maximum number of keys would you have to test?The following figure is the Cipher Block Chaining (CBC) mode to encrypt large messages. Which of the followings statement is *correct* regarding this mode? IV m₁ m₂ m3 C3 m4 C4 m5 C5 If a message contains two identical 64-bit blocks, the corresponding ciphertext blocks are also identical. Switching the order of two cipher blocks will not cause any detectable error in the plaintext. Duplicating a cipher block will not cause any detectable error in the plaintext. Deleting a cipher block will cause some detectable error in the plaintext. m6 E encrypt with secret key C6padding Question 11 Suppose we have a block cipher with block size 8-bytes (64-bits) and we will use the padding scheme described in class and used in the homework (PKCS #7, RFC 5652). How many bytes (octets) are added to a message consisting of 11 bytes when applying the padding scheme in PKCS7? Note: The message is written in hexadecimal. Each pair of digits (number or letter) is ONE byte (octet). You answer must be a number (for example, 3, 5, 9, etc.).
- 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…N blocks of plaintext (P1 to PN) are being encrypted in CFB mode into ciphertext (C1 to CN). Assume that two bits of C3 are erroneous (their binary values have flipped). What bits of C3, C4, and C20 are erroneous?Given a plaintext in HEX P1=AE1C, the encrypted cipher text is C1-87D2 with key K through stream cipher. Another Cipher text C2=6FF1 is encrypted by the same key K from P2 through stream cipher. Please decrypt the plaintext P2. You should transfer HEX to Binary number then calculate.(Use the property of XOR, don't calculate the key K