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Usually FPE is $Rank-LPE-DeRank$ Where LPE is length preserving encryption. The advantages of FPE schemes Preserving Formats and Lengths could be used against it too. There are two attack vectors specific to FPE (but they are by design !) Length Preserving This might aide to brute force attacks if the domain is too small. For example encrypting an IP ...


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The main problems using stream ciphers for this type of encryption are 1) you should not use the same key stream more than once and 2) linear operations such as cipher-text = plain-text XOR key-stream enables indirect plain-text modification simply by cipher-text changes (toggling a bit of cipher-text toggles the same bit of plain-text). For a better ...


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FE1 has no inherent maximum length; that limit is imposed by the implementation. The first obvious suggestion would be to use an alternate implementation without that limitation. Now, lets assume that's not a viable option; that you have to use this particular FE1 implementation. Now, the problem with chopping up the plaintext into fragments and ...


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The below is assuming a natural language is the one that has sentences from a well defined dictionary for that language (ex: oxford dictionary for english ). We can do this with the standard approach for FPE i.e $rank-encrypt-derank$. Build a $key-value$ pair map of all the words in the language of preference Where $key$ is the number and $value$ is the ...


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FFX is not malleable. It's a strong tweakable pseudo-random permutation, where the "strong" here indicates that both encryption and decryption look like random permutations from the attacker's perspective. In particular, there's no relationship between the plaintexts of closely related ciphertexts (aside from the trivial observation that different ...


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The tweak is a service that the encryption method provides for you. What it allows you to do is provide context separation for various encryptions using the same key. Here's the problem that it is trying to help with: suppose you use the same key to encrypt a number of items; for example, suppose you're encrypting all the items in one column of a database ...



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