Differences

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--- pgpfan:cipherfeedback [2021/11/12 21:21] – Spelling. b.walzer
+++ pgpfan:cipherfeedback [2021/12/17 12:55] – Failed to show what was being made into a TLA. b.walzer
@@ Line 9: / Line 9: @@
 If an attacker has some idea what is encrypted in the blocks they might be able to shuffle/duplicate/delete them in a way that might mislead you after they are decrypted. Because all the blocks with the same data will encrypt to the same value, an attacker might be able to see patterns that might give them some idea of what that data is.
-CFB (the thing that OpenPGP does) is a method that overcomes these shortcomings. Instead of encrypting the block you instead encrypt the last encrypted value, add the block in, and use this as the next encrypted value. Very simple.
+Cipher Feedback (CFB) (the thing that OpenPGP does) is a method that overcomes these shortcomings. Instead of encrypting the block you instead encrypt the last encrypted value, add the block in, and use this as the next encrypted value. Very simple.
 Patterns in the encrypted output are eliminated. Since CFB uses the popular technique of adding in the block to make the encrypted value it is possible to flip bits in the eventual unencrypted output. CFB imposes a cost to such modification however. Even a single bit flipped in a block will result in the entire next block coming out as random garbage. Attempts to shuffle/duplicate/delete the blocks will cause such random garbage at the edges of the modified areas. Attacks must work around this garbage and the corresponding lost data. As a result such attacks are significantly more difficult.