ConfusionConfusion defines making the relationship between the key and the cipher as difficult and as included as possible. In other words, the technique provides that the ciphertext provides no clue about the plaintext. Show In this regard, the relationship between the data of the cipher text and the value of the encryption has to remain as difficult as applicable. It is completed by spreading out the single plaintext digit over several Ciphertext digits, including when a single bit of the plaintext is changed. In confusion, it should influence the complete cipher text or change should appear on the complete cipher text and the relationship between the data of the ciphertext and the value of the encryption key is made difficult. It is achieved by substitution. The main goal of confusion is to create it very complex to find the key even if one has most of the plaintext-ciphertext pairs produced with the similar key and in this regard, each bit of the Ciphertext should be based on the complete key and in several ways on multiple bits of the key, changing one bit of the key must change the Ciphertext completely. DiffusionDiffusion can define to the property that the repetition in the statistics of the plaintext is “dissipated” in the statistics of the Ciphertext. In diffusion, the output bits should be based on the input bits in a difficult way so that in case one bit of the plaintext is modified, thus the Ciphertext should change completely in an unstable or pseudorandom manner. In diffusion, the statistical mechanism of the plaintext is used up into a high-range data of the ciphertext. This is achieved by having each plaintext digit influence the value of some ciphertext digits. Frequently, this is similar to having each ciphertext digit be influenced by some plaintext digits. Let us see the comparison between Confusion and Diffusion.
 Updated on 14-Mar-2022 08:24:07
Confusion and Diffusion Claude Shannon in his classic 1949 paper, Communication theory of secrecy systems, (available in pdf from here) introduced the concepts of confusion and diffusion. To this day, these are the guiding principles for the design of cryptographic algorithms. Roughly speaking, confusion obscures the relationship between the plaintext and ciphertext, while diffusion spreads the plaintext statistics through the ciphertext. A one-time pad relies entirely on confusion while a simple substitution cipher is another (weak) example of a confusion-only cryptosystem. A double transposition is the classic example of a diffusion-only cryptosystem. Note that confusion alone is, apparently, "enough", since the one-time pad is provably secure. But diffusion alone is, perhaps, not enough, at least using relatively small blocks. A stream cipher is simply a weaker version of a one-time pad and hence stream ciphers employ only confusion. Modern block ciphers employ both confusion and diffusion. The codebook aspects of such systems provide confusion analogous to---though on a much grander scale---a simple substitution. Well-designed block ciphers spread any local statistics throughout the block, thus employing the principle of diffusion. Where do public-key cryptosystems fit in? That is a very good question. What is the confusion property of product ciphers?Confusion means that each binary digit (bit) of the ciphertext should depend on several parts of the key, obscuring the connections between the two. The property of confusion hides the relationship between the ciphertext and the key.
Which of the following uses the confusion and diffusion concept?Both stream cipher and block cipher uses confusion. Only block cipher uses diffusion.
Which cipher discussed in this chapter employs both confusion and diffusion?A stream cipher is simply a weaker version of a one-time pad and hence stream ciphers employ only confusion. Modern block ciphers employ both confusion and diffusion.
Which of the following best explains the difference between diffusion and confusion in encryption?Confusion protect the relationship between the ciphertext and key. Diffusion protect the relationship between the ciphertext and plaintext.
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