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VOOZH | about |
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VOOZH | about |
In cryptography, confusion and diffusion are two properties of the operation of a secure cipher. Both Confusion and Diffusion are used to stop the deduction of the secret writing key, these properties, when present, work to thwart the application of statistics and other methods of cryptanalysis.
Confusion is employed for making uninformed cipher text whereas diffusion is employed for increasing the redundancy of the plain text over the foremost part of the cipher text to make it obscure. The block cipher solely depends on diffusion, where else, confusion is employed by both stream and block cipher.
In general, the idea of confusion is to obscure the relationship between the key and the plaintext on one hand, and the ciphertext on the other. This is usually done by intricate methods of substitution, by replacing one piece of data with another in a disorderly disordered way. The use of confusion makes it possible to design the key in a way that even if the attacker has part of the key, it will not be possible to deduce the other part of the key.
Example: The introduction of confusion is done through a substitution cipher whereby each letter of the plaintext is replaced by a different letter in accordance with a relatively complicated set of rules.
Confusion = Substitution a --> b Example : Caesar Cipher
While in diffusion, it is a cryptographic technique that would ensure that the effect of one or one plaintext digit would be evenly spread out to a number of ciphertext digits, thereby minimizing on the redundancy on the plaintext. The aim here is to spread the statistical structure of the plaintext over the entire ciphertext so as to mask patterns of data. It is usually done by use of permutation as well as; transposition.
Example:In a block cipher, diffusion is responsible for the occurrence in which change in one bit of the plaintext has an influence on many bits of the ciphertext so as to make it difficult for attackers to identify any patterns.
Diffusion = Transposition or Permutation
abcd --> dacb
Example : DES
| Confusion | Diffusion |
|---|---|
| Confusion is a cryptographic technique that is used to create faint cipher texts. | Diffusion is used to create cryptic plain texts. |
| Confusion is possible through substitution algorithms. | Diffusion is possible through transposition algorithms. |
| In confusion, if one bit within the secret is modified, most or all bits within the cipher text also will be modified. | In diffusion, if one image within the plain text is modified, many or all image within the cipher text also will be modified |
| In confusion, vagueness is increased in resultant. | In diffusion, redundancy is increased in the resultant. |
| Both stream cipher and block cipher use confusion. | Only block cipher use diffusion. |
| The relation between the cipher text and the key is masked by confusion. | The relation between the cipher text and the plain text is masked by diffusion. |
Named confusion and diffusion, both are equally essential to the modern encryption algorithms’ robustness. Where as confusion conceals the link between the cipher text and the key, diffusion guarantees that the cipher throroughly scatters the impact of the plain text. Both of them contribute to the effective safeguard against the cryptographic attacks which makes encrypted data more secure.
