# Questions tagged [3des]

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

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### Would this 3AES-192 scheme achieve 384-bit key security with just a 384-bit key?

For starters, I don't need any don't-roll-your-crypto stuff. We're discussing a hypothetical. So the idea is 3DES needs 3x the key size and achieves only 2x key size bit security. So using the 3x ...
1 vote
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### Input/Output size of compression functions

I know that DES has 56 independent key bits, and that 3DES has 168 independent key bits by using 3 seperate 56-bit DES keys. 3DES also has a block size of 64 bits. If I use 3DES as the underlying ...
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### Exploit 3DES-CBC with known checksum of plaintext and repeated IV

I came across the following enterprise encryption scheme. I laughed when I first saw it, but I'm not a specialist and I'd like to know how bad it really is. 3DES-CBC k1=k2=k3 for 3DES IV for CBC is ...
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1 vote
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### Triple DES 1 key to simulate 3 keys

I saw a statement that the probability of finding a key $k'$ to simulate 3 keys $k_1$, $k_2$, $k_3$ is neglectable: $\mathrm{Enc}(k_3,\mathrm{Enc}(k_2,\mathrm{Enc}(k_1,x))) = \mathrm{Enc}(k′,x)$ When ...
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### Security Strength of Symmetric vs Asymmetric Ciphers

NIST SP 800-57 Part 1 rev 5 section 5.6.1.1 gives following comparison between different encryption types. For example, it shows that 3TDEA, RSA-2048, ECC224 provides security strength of 112 bits. ...
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### Why are credits cards using 3DES instead of AES?

Why are credit cards using 3DES instead of AES? As far I understood, even DES3 is less secure than AES. Why it is still used? I searched already in the internet and forum to check out if it is ...
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### What is the importance of superencryption?

Please, can any extensively explain the importance of super encryption in relation to attacks experienced by single standard algorithms
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### What is DES-EDE3-CBC?

I came across DES-EDE3-CBC and a quick search didn't yield a clear explanation of what it is. Clearly, DES is the Data Encryption Standard and CBC is the Cipher Block Chaining mode. EDE is probably ...
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1 vote
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### Increasing the parallelization of Triple-DES

Triple-DES encrypts with the first key, then the second key, then the third key. Two keys are sitting around waiting. Why not encrypt with all three keys at the same time? You take 192 bits of ...
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### What's the probability distribution of 3DES keys' key check values?

Do the key check values of two-key 3DES keys have a uniform distribution? If not I'm curious as to what the distribution is. I ask because I want to know how safe it is to use a key's KCV as an ...
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### How to make DES more secure without switching from des state to another cryptography system and what are limitations of DES?

How to make DES more secure without switching from des state to another cryptography system and what are limitations of DES? Is there any 3 ways to make des more secure?
1 vote
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### Generate unique random values for unqiue input values

I'm going to generate unique random values based per a range of unique input values. In other words I have range of input values which these numbers are part of a series (like a range of serial ...
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### 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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1 vote
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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 ...
1k views

### 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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1 vote
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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 ...
1 vote
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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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1 vote
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### 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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1 vote
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### Would Triple DES-X with 7 keys be much slower than standard Triple DES?

Since a single hardware pass of an XOR with a 64-bit key is speedy, would Triple DES-X with seven 64-bit keys used in the following manner be virtually identical in terms of code size, memory ...
1 vote
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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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### 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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1 vote
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### 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?
7k views

### 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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### 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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### 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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