Questions tagged [ecb]

Electronic Code Book (ECB) is a mode of operation for a block cipher, with the characteristic that each possible block of plaintext has a defined corresponding ciphertext value and vice versa.

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How can I encrypt with a matrix key using ECB mode? [closed]

Given this plaintext: 101010101010, and the block is 3, with a IV = 000 and the key as k = |1 2 3| |2 1 3| What are the required steps to get the same result like these in ECB mode: c1 = Ek(m1) = 011, ...
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In AES-128-ECB, if byte 15 is over 128, the padding block changes value. What's the reason for this behavior?

For example, if we run this openssl command: openssl aes-128-ecb -a -in <(echo -n "AAAAAAAAAAAAAAAA") -K "deadbeefdeadbeefdeadbeefdeadbeef" ...
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Attacking AES ECB

this is a school challenge. I have a cipher file which is the audio file, and no key of course, encrypted with AES ECB mode. The size is around 550 Kb. I know the key size used is 16 bytes, and I have ...
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Why is ECB mode unsafe if the key is kept secret?

this is my first post so I apologise if the formatting of my post isn't perfect. I should start off by saying that this post is not for any malicious intent, rather for curiosity and understanding AES ...
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How AES diffusion (permutation) does not impact ECB penguin pattern with in each block?

As per my understanding AES introduces diffusion in each block it encrypts even with ECB as mode of operation. If that is the case how the patterns are retained in each block? In this blog https://...
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Clarification on expected number of plaintext, ciphertext pairs needed to identify AES keys

I'm aware of the many questions on this topic, but I'm still not sure what went wrong with my reasoning here below. I'm assuming use of AES with key size $2^{256}$ and messages of size $2^{128}$, ...
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Is it possible to use aes-ecb-256 decryption algorithm as customer key derivation function to generate the aes key?

I'm sorry if I'm going horribly wrong - I am new to this stuff. My question is: KDFC1,KDFC2,KDFC3 is defined by myself. Key1 is come from outside . Is it possible to use the aes-ecb-256 decryption ...
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How shall I imagine the prefix Chosen Plaintext Attack (CPA) on ECB mode in practical terms?

I know quite well how prefix attack works for ECB mode as described in https://www.linkedin.com/pulse/short-note-prefix-chosen-plaintext-attack-cpa-ecb-mode-hannes-salin Great, but in most situations ...
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How is ECB secure? [duplicate]

Setting aside legitimate concerns such as lack of CPA security (not to speak of malleability issues) and thus near-universal insuitability of AES-ECB for general purposes, I thought I recalled reading ...
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Decryption considering AES OFB and ECB

I have the following pseudo code considering a ransomware methodology to encrypt files: cFile = AESEncrypt(sessionKey, pFile, OFB, iv) keyBlob = AESEncrypt(masterKey, sessionKey, OFB, iv) ivBlob = ...
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what will be the impact of a 2-bit error in a ciphertext block for decryption if AES is used in ECB, CBC and CTR mode?

So I was reading about 1-bit error propagation for AES mode and how it propagates in various modes. I was wondering how error would propagate in ECB, CBC and CTR modes if it was a 2-bit or a 3-bit ...
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How strong would be create a password through AES ECB encryption?

Suppose that I want to use a "poor man" password management working as follows: 1. I choose and remember one single master password (for example "78HK+jm?329"); 2a. for any bank, ...
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recover plain text from cipher text in AES-128 ECB mode [duplicate]

I have a scenario where I do not have the key but I have plaintext 1, ciphertext 1, and ciphertext 2. Ciphertext 2 is built using the same key that was used to build ciphertext 1. Is there somehow a ...
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ECB... lacks diffusion(?)

I noticed that the wikipedia page for 'block cipher modes of encryption' states, "The disadvantage of this method is a lack of diffusion.", referring to ECB mode for block cipher encryption. ...
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Does hashing an ECB encryption with a strong hash function produce a secure MAC?

Does applying a strong hash function like SHA-256 to the ECB-encryption of a message (using some secret key $K$) produce a secure mac? For example, given a message $m$, would a simple mac construction ...
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Prove that ECB-mode of a block cipher is not EAV-secure

I know that ECB-mode of block cipher is not recommended to use as it is not secure and is not even EAV-secure. However, I still don't get how to prove that it is not EAV-secure and what adversary is ...
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Online AES Calculator

I am currently looking into how AES works and found a calculator online: http://testprotect.com/appendix/AEScalc I understand that the AES process has 10 rounds of calculations. Does this mean that ...
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Which encryption technique should be adopted to keep the search functionalities?

I am in exactly the same situation as described in this post. I must be able to encrypt data from a client workstation then send it to an untrusted server (encrypted at rest), then decrypt it only on ...
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AES-ECB Reverse attack CTF [closed]

We have a key representing an SHA-256 hash in HEX, and we have the key in AES-ECB. We also have a file with plaintext to cipher messages that were encrypted with our key. How could we find this key? <...
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Is ECB mode more suitable than CBC mode while encrypting a long bit string?

I know that ECB is less secure than CBC, but will it be suitable for encrypting a long bit string?
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Byte At A time ECB Attack

This is my first post on stack overflow/stack exchange so please excuse me if I asked the question in a bad way or the format is bad. I am currently working through the cryptopals challenges and I got ...
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Help needed for IBM KCV

I found old key letters used in EFT HSMs with TDES keys, parted in two halfs. The check value printed on this letters is called IBM CV and doubled IBM CV. My newer HSM does not support this kind of ...
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Combining CTR and ECB modes to prevent attacks

In Reusing AES-CTR Keys and IVs for File Encryption, the OP was asking about a composite encryption scheme $$C_i = E_K\left(P_i \oplus E_K\left(IV + i\right)\right)$$ which is basically just a CTR ...
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AES 128-bit encryption - not getting expected results

I am trying to implement AES encryption on my own (128 bit key and ECB mode for now) and I can't seem to get expected results. From what I understand about AES algorithm is that it divides message in ...
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AES Padding (Nullbytes vs PKCS7)

I currently implement the AES(128,192,256)(ECB,CBC). Does the type of padding affect security? I just want to fill the blocks with null bytes.
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How to find Key with DES, ECB hash and plaintext [closed]

I have two ciphertexts. Encryption algorithm: DES in ECB mode. Ciphertext: 72EE3532F904CE2AAA966C723C463F294CA8AB1C11E9E0B304BBB6A8E2BD1F34 Plaintext: DetectedSpambotsRemailedMalwares Ciphertext: ...
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What exactly is the problem with using electronic codebooks as a block cipher mode [duplicate]

I was wondering why it is a problem with using ECB as a block cipher mode
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OpenSSL not producing messages of expected size

I have a 16 byte file, and after encrypting it, its size weirdly changes. ...
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How does AEAD guarantee authenticated encryption and plain AES does not?

This is a follow up to my earlier question. This is more out of curiosity in how AEAD (like CCM or GCM) works compared to encryption in other modes (like CBC or ECB). Suppose you have AES-256-CBC ...
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How can frequency analysis be applied to modern ciphers?

I am building a computer program that deciphers Caesar, Vigenere and monoalphabetic substitution ciphers. All of those are susceptible to frequency analysis. However, it does not seem to be real-world ...
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How to prove that ECB mode is not CPA secure?

I am new to cryptography and I do not know how to prove the ECB mode is not chosen plaintext attack (CPA) secure.
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What are the length of ciphertexts when 16 bytes and 18 bytes of plaintext using ECB?

What are the length of ciphertexts when 16 bytes and 18 bytes of plaintext are encrypted with AES using ECB mode?
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Meet-in-the-middle attack (different block cipher modes)

Does a meet-in-the-middle attack on depend on the used modes for block ciphers? encryption: $C_i$ = $D_{K2}$($D_{K1}$($E_{K1}$($P_i$ $\oplus$ $C''_{i-1}$))) $\oplus$ $C'_{i-1}$ and $IV_1$ = $C''_0$ = ...
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Meet-in-the-middle attack (on custom encryption scheme) [duplicate]

This is a question I had from an exercise session. Exercise: First we do DES in CBC encryption mode using a key $K_1$ and $IV_1 = O^n$. Then we do DES in ECB decryption mode using $K_1$. And then DES ...
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Symmetric encryption construction (meet-in-the-middle attack)

This is a question I had from an exercise session. First we do DES in CBC encryption mode using a key $K_1$ and $IV_1 = O^n$. Then we do DES in ECB decryption mode using $K_1$. And then DES in CBC ...
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LoRaWAN 1.0.2 Session Key Security

I am reading about LoRaWAN 1.0.2 specification. For the confidentiality and integrity of the comunication the protocol generate two session keys, the NwkSKey and the AppSKey (part 6.2.5 of the ...
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Can ECB be turned into a secure algorithm by adding obfuscation of the plaintext patterns?

Just to preface this I'm very new to cryptography. However, I've been reading that ECB should not be used under most circumstances due to its symmetry which allows attackers to gain information about ...
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What's the reason for Monte Carlo tests for block ciphers?

NIST specifies that implementations were required to create Monte Carlo test vectors for ECB and CBC mode for the AES competition. What's the reason for these tests? The only thing I can think of is ...
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In which cases AES doesn't need IV?

I was trying to decrypt a text encrypted with AES and ECB mode. I did try several keys and IV. I solved it by ignoring IV. (The IV was given, but it was maybe a distraction) My question is in which ...
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Performing a dictionary attack on RSA/ECB with no padding

I have the exponent $e=2^{16}+1$ and modulus $n$ (154 digit number) of an RSA public key along with the ciphertext (64 bytes) encrypted using the same key with RSA/ECB and no padding. I am required ...
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Security of AES after key expansion 4-MB with ECB and CBC

My question is, how does the security depend or change if I encrypt with AES-128 in total 4-MB of Data? With Electronic Code Book Mode and Cipher Block Chaining Mode ? Does an adversary still ...
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Is it possible to find the key for AES ECB if I have a list of plaintext and corresponding ciphertext?

Assume I have a list of plaintext text and its corresponding ciphertext which was created using a specific key with AES in ECB mode. Can I recover that key? If, how big does the list of plaintext ...
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Encrypting AES in ECB mode

I'm fairly new to cryptography and am starting to understand this weird art of Mathematics and theory. One thing I am trying to understand and do is encrypting a plaintext into ciphertext using AES in ...
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Is AES ECB good enough for key spreading?

My apologies if I get my terminology wrong - I am new to this stuff. I am writing a routine (in c) to encrypt plaintext. I am using TinyAES to perform a CBC on the plaintext and sending a (pseudo)...
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Variation on the ECB Penguin problem [closed]

So this is an age-old example of why encrypting images with ECB is a terrible idea, since the underlying pattern of the image remains the same. Referenced from: If you encrypt an image (AES), is it ...
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With DES, is ECB encryption mode equivalent to CBC with null IV for short data blocks?

I got to this by experimentation, but can someone maybe provide an explanation for this?
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Which block cipher mode to use?

I am working on securing a chat application, and I am not sure about which block cipher mode I should use. I am aware that I should avoid ECB as it's insecure, but what about CBC? I have watched ...
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Security of AES ECB for 128 bit random data

I am using AES ECB mode to encrypt and decrypt 128 random data. I have read on drawbacks on using ECB but it seems that it is feasible to use it for random data. However my concern is that my ...
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Can I work around these padding issue in AES 256 ECB due to Reed solomon encoding?

Disclaimer: I do NOT believe AES-ECB to be at all useful for encryption. That said, due to time and bureaucratic issues that I'm not in control of, I need to use AES-ECB. I get packets of data that ...
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Are there any benefits to using ECB over CBC?

From what I have understood about ECB and CBC, CBC is far better as it doesn't reveal any pattern. There have been several questions here about how ECB is bad: Should I use ECB or CBC encryption mode ...
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