20 questions linked to/from Bit Flipping Attack on CBC Mode
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### AES-CBC ciphertext manipulation with known IV and plaintext! [duplicate]

I'm currently practicing on a purposely flawed login page, where I have to change the value of a cookie to enter. The cookie is an encrypted and encoded form of a simple JSON string with fields "admin"...
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### Alter CBC plaintext by altering IV [duplicate]

I am building on this answer. Essentially I have an initialisation vector $iv$, a ciphetext $c$ and a plaintext $p$. The plaintext was encrypted using AES CBC. The aim is to modify the first 4 ...
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### Easy explanation of “IND-” security notions?

There are many schemes that can advertise themselves with certain security notions, usually IND-CPA or IND-CCA2, for example plain ElGamal has IND-CPA security but doesn't provide IND-CCA security. ...
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On paper, it sounds *very* good to me: secure fast (in my tests it's somewhat slower than ECB (but without most of the weaknesses, more on that below) but faster than every other alternative I tested,...
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### Why does error propagation in CBC mode encryption affect two blocks?

From Wikipedia: Error propagation It was common to discuss the "error propagation" properties as a selection criterion for a mode of operation. It might be observed, for example, that a one-...
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### Are there any cryptographic algorithms, which lets the user apply some modifications on the encoded data, without decoding it?

I would like to encode some data with a key, and send it to a third party. They don't know the key to decode it, but I would like to make it possible for them to apply some modifications on it. Then ...
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### Example of a cut-and-paste attack on CBC

I am reading the cryptography book by Stamp and there is a cut-and-paste attack on $ECB$ and this is easy to follow because $ECB$ is relatively simple, the problem is that I would like to see an ...
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### AES-CBC decrypts to wrong output?

Someone I know showed this to me, and I can't put a finger to why it's happening. Am I missing something? They encrypt the text, and the output is really guessable. $u\to t$, $i\to h$ (it's one letter ...
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### Is CTR more secure than CBC?

In cryptography, a block cipher mode of operation is an algorithm that uses a block cipher to provide information security such as confidentiality or authenticity. A block cipher by itself is only ...
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### using different IV and SALT with AES-CBC but same KEY

I'm working on this project where a client can send a message, now obviously sending it in plainText is not very smart. So I decided to Encrypt it with AES-CBC. Now, each time I encrypt something, ...
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### Can I alter encrypted data without decrypting it? [duplicate]

I didn't find a direct solution for it. Can I modify encrypted data without accessing it? If there is an example, I would appreciate it.
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### 128 bit AES CBC bit flipping on second block

I have a 128 bit AES cipher in CBC Mode with the IV prepended to the message. I am aware of the security issues here, but that is exactly the point of my example. I would like to change the plain text ...
696 views

### 64 bit clock cipher with CFB mode. One-byte defected from ciphertext. What is the number of bits defected from plaintext

I have a question from an exam; We encrypted a message of size 100 Bytes with CFB. In the transmission, byte number 12 got defected. How many bits defected will be in the decryption. The answer is 72 ...