Questions tagged [3des]

A block cypher encryption algorithm built from applying three iterations of the original DES algorithm.

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187 views

How fragile is 3DES nowadays?

Mastercard, Visa, and several other organizations use 3DES to encrypt and decrypt credit card data. The sweet32 attack placed 3DES in the spotlight, but how fragile is 3DES for a very small amount of ...
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Periodic re-keying during full drive encryption

A man encrypted a hard drive in 1996 using three key 3-DES with a 64 bit IV and CBC mode in the following manner using known 1990s algorithms on a 1996 PC. Here is how he did it. Start with a ...
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Can we use Bitcoin miner to break 2Key 3DES, if yes how long it takes?

As ASICs are specifically designed to generate the hash for a block of a block chain. which is much faster than other GPUs which are used to break 2key-3DES. can we use Array of ASICs to break 2key-...
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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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3DES security when K1=K3

I am mainly looking for security on 2-key $\operatorname{3DES}$ implementation where $K_1=K_3$. How hard or easy is it to crack $\operatorname{3DES}$ when $K_1=K_3$?
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Disrupting MITM attack against 3DES by intermingling plaintext and inter-mediate ciphertext between rounds

Let's say someone implements 3DES with three separate 56-bit keys and an attacker is attempting to execute a MITM attack. Here is the encryption plan designed to attempt to disrupt the MITM attack, or ...
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Frequency Analysis on DES, AES, 3DES using Cryptool2

I am trying to analyze symmetric block ciphers like DES, 3DES and AES, using Cryptool 2. I want to do a frequency analysis on each of these ciphers, in order to comment whether this is an effective ...
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334 views

TDES (Triple DES) DUKPT decryption

We have a POS (Ingenico) that uses DES3-CBC encryption using a derived key. It sends encrypted data, and 10 bytes size Key Serial Number (KSN). I tried to use ...
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Is there a feasible way to reconstruct the key from the (Triple-)DES round key?

Assume there is a closed source application which uses Triple-DES with a fixed/hardcoded key to decrypt large amounts of data. Someone managed to extract the round keys from a process memory dump and ...
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Why didn't people redesign the key scheduling algorithm of DES to use longer keys instead of using 3-DES?

To overcome short key length of DES, Triple DES was devised. What would go wrong or why didn't people redesign the key scheduling algorithm to use longer keys?
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2DES and 3DES against a DES build with complimentary

I saw this complicated question and I am not really sure about it, would appreciate your view on it. Is the following build stronger than 2DES or 3DES with 2 different keys (or even normal DES)? $...
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Behavior of Iterated 3-DES

When reading ''Algebraic Cryptanalysis'' by Gregory V. Bard, Springer Editions, I got confused by this sentence: Suppose there were three naïve Cryptography students, who choose to use 3-DES ...
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Do I need verifiable shares?

I'm using Shamir's secret sharing in a 2:3 system. Thus a secret Key is split in 3 subkeys (KeyS:KeyC:KeyT) I've 3 entities at ...
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Extracting RC4 and 3DES keys from system memory

I have read papers [1], [2] that have presented techniques on extracting symmetric encryption keys from memory during the process of encryption. There are tools [3] that can extract AES keys from ...
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1answer
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How DES/AES can guarantee by feeding different secret keys, the encrypted outputs are different?

I am learning the meet-in-the-middle on DES attack. I understood the basic logic behind how it is performed; however, one further question is: why can we guarantee to find one and only one pair of k1 ...
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Using 3DES decryption to get a specific result

I want to get 3DES to get a predictable result; assume I have: key: [any] data: [any] then I want to apply 3DES decryption on key and data to get a specific ...
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I'm curious on methods of encrypting files using C++ [closed]

I'm making a personal security tool in C++ and was curious how I would go about encrypting files in C++. If anyone has a method that would be great, and more specifically I was interested in 3DES ...
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Is it possible to perform a meet-in-the-middle within a block cipher?

Standard meet-in-the-middle explanations show that you can perform a meet-in-the-middle attack on a repeated block cipher such as double-DES (performing DES twice in a row). However, block ciphers ...
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Determine Encryption Used by Examining File Headers?

I have an encryption problem that I hope you might be able to help me with. I have a bunch of encrypted files. Some of them were encrypted with ...
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1answer
601 views

What are the separate single DES keys from a triple DES key?

Suppose my 192 bit triple DES key (in hex) is 0123456789ABCDEFFEDCBA987654321089ABCDEF01234567 What are the keys for the separate single DES operations? In this ...
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498 views

Is there any encryption algorithm that, with small change in input will produce big change in the encrypted output?

As stated in the title, I'm looking for an encryption algorithm with the characteristics that, when inputs are slightly different, the encrypted output will be VERY much different, to the point that ...
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1answer
429 views

Would XDES be more secure than 3DES, where X is a number > 3?

Would XDES be more secure than 3DES, where X is a number > 3? Like 10DES... If so why aren't we using it?
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Decrypt 3DES with a key and a nonce? [closed]

I have been tasked with moving an authentication service from our provider to somewhere else. The code base for the current service is not available to me, but I know these things: I have a 65 ...
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DES - encrypt 3 times - DES(DES(DES, k), k'), k) - stronger than 2DES with 2 different keys?

What if were to use DES in the following way: For a given plaintext x and key k we will perform: ...
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What is the keyspace of 2-key 3DES?

I am assuming that 2-key 3DES is equivalent to 2DES. I know the key size is 2x56 = 112 bits. Is this key size the same as the keyspace? e.g. Would the keyspace be 112 bits ($2^{112}$)?
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3DES Feasibility and Security [closed]

Questions are as following: Is 3DES still feasible (in terms of security and performance) to use? Is 3DES safe to use in ECB mode? Every time on giving the same input (plain text) to encrypt via 3DES ...
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Encrypting current time using 3DES as a signature

I came across a peculiar system for generating "signatures" ("signatures" is within quotes because this is a bad use of 3DES) in the wild. It works as follows: a symmetric key is generated and used ...
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543 views

How can two keys have the same KCV?

I have two keys and they have the same KCV. How is this possible? I have encrypted data with both keys and I have the same result. Both keys are the result of the derivation of the same IMK, one was ...
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Triple Data Encryption Standard [closed]

Based on this, it looks like something slightly wrong. What would need to be adjusted at the transmitter side to allow the receiver to decrypt the message/data?
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Why would anyone choose 3DES over AES in software?

I'm well aware of what NIST and PCI say about the usage of 3DES and its deprecation/disallowance and I also know that AES is the actual recommended standard for software and hardware encryptions. I'm ...
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557 views

3DES CFB vs CFB8 modes

What is the main difference between CFB and CFB8 modes in 3DES? Is it only a change in block size from standard 8 byte to 1 byte when doing 3des and XOR? I cant find any pseudocode for this CFB8 mode?...
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Does C# Triple DES Encryption need 128 bit key or 192 bit key [closed]

I have the following code in C# ...
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Can I find the encryption key if I know the plain text and the encrypted text (DES and AES)?

If I have the plain text and its output after encryption with a key K1, is it algorithmically feasible to find K1? I am specifically interested in the cases of DES and AES encryption algorithms.
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Discrepancy between 3DES in OpenSSL and PyDES [closed]

I'm trying to encrypt some data using triple DES ECB, but I get a discrepancy between OpenSSL and the pyDES library I'm using. When trying to get a KCV value, I'm using a file consisting of 8 bytes ...
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Will two KEK's provide the same KCV or should these be different?

If you were to have an MDKac key that you need to send to two parties you would need to encrypt this key with two different KEK/ZCMKs. Will the KCV of the MDKac under KEK1 provide the same KCV as ...
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1answer
3k views

How 3DES work in a simple way?

As I understand DES, It encrypt 64-bit plaintext block with 56-bit key (ECB). So if ...
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1answer
525 views

Cryptographic methods that do not use prime numbers?

Does anyone know any cryptographic methods that do not use prime numbers? If so, which ones?
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Questions about future and session key generation in DUKPT process

As I understand this process is done in the client device for generating a unique key per transaction: inject generated IPEK to client device; generate set of future keys (actually 21 future keys) ...
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Does multiple encryption cycles (using the same password for each iteration) offer any security?

Does running a plaintext through AES multiple times with the same password offers any security benefit akin to triple DES? Note that I'm assuming “same password for each iteration”.
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Is Triple DES still considered safe to use?

What it says on the tin. Is it still used in things like TLS?
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Retrieving the 3DES decryption key from plaintext and ciphertext?

I have a hex key that I want to decrypt with a 3DES key in mode ECB. For example: ...
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1answer
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Why isn't the maximum security of triple DES 48 * 2 vs 56 * 2?

The security of quadruple or even more encryption isn't much more than that of double encryption. But each round also counts as one encryption. So why isn't triple DES only 96-bits secure?
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HBCI Encryption/Decryption

I need help during implementation of C# interface (.NET framework) for encryption of messages which are sent to/from HBCI (Homebanking Computer Interface) server according to RDH-10 standard. ...
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Modes of Triple DES - When to use each?

I'm studying for CISSP certification & am using Shon Harris Exam Guide. It states that there are 4 modes that Triple-DES can be used in: DES-EEE3 DES-EDE3 DES-EEE2 DES-EDE2 I understand these ...
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Does a 128bit 3DES need billions of years to decrypt using brute force attack? [duplicate]

a) I did some research and there are two opinions.. some say it cracks in several years and others say it doesn't crack for billions of years USING BRUTE FORCE ATTACK...
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How can I attack a Triple-Block cipher with 2 keys (like 3DES) with a cost of ≤ 2⁵⁶

I am trying to solve something and I have but I have no idea anymore. Maybe anyone of you has an idea/solution/hint. Given is a block cipher $F$ with key length $n$. It looks like this: $$c = ENC_{k1}...
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backward-compatible triple encryption

I was asked to encrypt a message by applying backward-compatible triple encryption using the 8-bit key $k = (k_1, k_2)$ where $k_1≠k_2$. I'm a little confused because I thought all 3 keys had to be ...
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1answer
835 views

Using MITM to attack three keys 3-DES encryption?

I know that MITM can break three keys into two parts $(K_1,K_2)$ and $K_3$ where the worst time complexity is $2^{112}$. My questions is whether we are able to break three keys $(K_1,K_2,K_3)$ into ...
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DUKPT PIN decryption

I have actually been able to carry out a DUKPT data decryption successfully, which was also been confirmed with the BP-Tools - Cryptographic Calculator. After understanding the differences between ...
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Special case of 3DES

3DES uses EDE as it is backward compatible to single DES, but consider the following case $K_1$=$K_2$=$K_3$ which one is more secure EDE or EEE.