Question

In: Computer Science

A message has been encrypted by Bob using row transposition cipher to give the following ciphertext:...

A message has been encrypted by Bob using row transposition cipher to give the following ciphertext:

TTNA APTM TSUO AODW COIX KNLY PETZ

However when Bob shared the key with Alice, it got copied multiple times and looks like:

…. 6 7 4 3 1 2 5 6 7 4 3 1 2 5 6 7 4 3 1 2 5 6 7 4 3 1 2 5 6 7 4 3 1 2 ……

You see a series of numbers repeating. However you do not know which number

to start the key with.

  1. How many keys will you have to try to find the correct key (maximum keys you may have to try)?

  2. Find the correct key. Describe the process you followed to find the key.

  3. Decrypt the ciphertext given above and find the plaintext.

Solutions

Expert Solution


Related Solutions

decrypt the ciphertext xyatqyvaxpagjdpglax encrypted by the affine cipher. also explain is there alphabets which will...
decrypt the ciphertext xyatqyvaxpagjdpglax encrypted by the affine cipher. also explain is there alphabets which will not change after ecnryption
Binary file IO Suppose a file has been encrypted using the Caesar cipher as described above,...
Binary file IO Suppose a file has been encrypted using the Caesar cipher as described above, and you know the secret key. Write a program to decrypt (or decode) the file. Your program will prompt the user to enter an input file name for the encrypted file, an output file name for the unencrypted version of the input file, and the secret key. Create a DataInputStream for the input file and a DataOutputStreams for the output file. Next, read the...
Using playfair cipher, decrypt the ciphertext “GKSKHALTYZ” using the keyword “UNIVERSITY”
Using playfair cipher, decrypt the ciphertext “GKSKHALTYZ” using the keyword “UNIVERSITY”
Suppose an attacker obtained 128 bits of ciphertext that were encrypted using an encryption algorithm whose...
Suppose an attacker obtained 128 bits of ciphertext that were encrypted using an encryption algorithm whose keys are known to be 128 bits long. How effective is an exhaustive key search if the attacker does not know the encryption algorithm used? Provide an example of when data integrity is more important than data confidentiality? Suppose you have been asked at your new job to recommend the strength of encryption needed to protect the contents of a database. Draw up a...
Below are six ciphertexts of the same message encrypted using the following four classical ciphers available...
Below are six ciphertexts of the same message encrypted using the following four classical ciphers available in CrypTool: Caesar (shift), Substitution, Vigenere and Permutation. Do your best to match ciphertexts with a cipher that could have been used to obtain the given ciphertext. If you are uncertain, you can list several ciphers per each ciphertext. Justify your answer. Find the plaintext, by breaking the Caesar (shift) cipher, and then find the keys for at least 3 ciphers used to encrypt...
Write a Java program to encrypt the following message using the RC4 cipher using key CODES:...
Write a Java program to encrypt the following message using the RC4 cipher using key CODES: Cryptography is a method of protecting information and communications through the use of codes so that only those for whom the information is intended can read and process it. Instead of using stream length 256, we will use length 26. When encrypting, let A = 0 to Z = 25 (hence CODES = [2 14 3 4 18]). Ignore spaces and punctuations and put...
Cryptography: Using columnar cipher, find the plaintext and the key that generated this ciphertext: ykccjosaiawiekhriogrrlrni Keep...
Cryptography: Using columnar cipher, find the plaintext and the key that generated this ciphertext: ykccjosaiawiekhriogrrlrni Keep in mind that only letter j was used for padding. (Show your detailed work)
Write a Java program that uses the RC4 cipher algorithm to encrypt the following message using...
Write a Java program that uses the RC4 cipher algorithm to encrypt the following message using the word CODES as the key:   Cryptography is a method of protecting information and communications through the use of codes so that only those for whom the information is intended can read and process it. Instead of using stream length 256, we will use length 26. When encrypting, let A = 0 to Z = 25. Ignore spaces and punctuations and put the message...
Give two ways to encrypt a partial block cipher. Your first method should result in ciphertext...
Give two ways to encrypt a partial block cipher. Your first method should result in ciphertext that is the size of a complete block, while your second method should not expand the data. Discuss any possible security concerns for your two methods.
Based on Rectangle transposition techniques, decrypt the following cipher text “LTHBPEEMOSRAIAESIGCVDENTUUBWEFSONES”. Then use the same key...
Based on Rectangle transposition techniques, decrypt the following cipher text “LTHBPEEMOSRAIAESIGCVDENTUUBWEFSONES”. Then use the same key to encrypt the following plain text “the automorphism group is more difficult”.           there is no given key
ADVERTISEMENT
ADVERTISEMENT
ADVERTISEMENT