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Questions tagged [3des]

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

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2answers
73 views

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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1answer
54 views

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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2answers
72 views

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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1answer
60 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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1answer
75 views

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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1answer
2k 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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1answer
170 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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1answer
265 views

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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4answers
2k views

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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0answers
685 views

Triple DES encryption/decryption in nodejs

In Delphi , we are encrypting the password using TripleDESEncryption algorithm. We use the key as an array of byte [0..15]. Then the input string is converted is first saved to stream and then sends ...
0
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1answer
340 views

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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1answer
125 views

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
1k 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
297 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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1answer
694 views

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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0answers
98 views

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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2answers
13k views

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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2answers
1k views

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: ...
2
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0answers
140 views

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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0answers
79 views

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...
9
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1answer
766 views

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}...
0
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1answer
437 views

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 ...
2
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1answer
395 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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1answer
723 views

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 ...
4
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1answer
227 views

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.
3
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1answer
90 views

Sweet32: Can a single 8 byte block session ID be exploited by this vulnerability?

Im currently developing a authentication scheme. The authentication scheme will use a 64 bit encryption to encrypt its session ID. Here is how the authentication system will work: For each session, ...
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3answers
13k views

Calculating 3DES Key Check Value (KCV)

I am trying to verify a Triple DES Key Component generated by PC Crypto. The key portion is: E6F1081FEA4C402CC192B65DE367EC3E and the KCV value that should be ...
3
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1answer
605 views

Why does 3DES need private key to decrypt?

I create two files, my.cer and my.pem ( include certificate and private key), I encrypt a file with my.cer, I use openssl smime -encrypt command. When decrypting data, it needs my.pem. I think 3DES ...
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1answer
104 views

Why would a 3DES key decrypt one block, but not the next?

I'm trying to crack an encrypted data stream. It appears to be using a 64-bit 3DES key (as written in the application logs), and in fact using that key does correctly decrypt the first 64-bit packet ...
1
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1answer
2k views

Triple DES with 2 keys

Suppose triple DES is performed by choosing two keys $K_1$ and $K_2$ and computing $C = T (T (T (L, K_1), K_2), K_2)$. How to attack this modified version with a meet-in-the-middle attack, in which ...
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2answers
347 views

What is transaction capacity of a POS using 3DES DUKPT?

I am looking for the transaction capacity of a Point-Of-Sale device using 3DES DUKPT. Once all keys derived from the future key set are exhausted (1M or 500K?), how will the POS be reloaded with a new ...
3
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1answer
2k views

Effective key length of Two-Key Triple-DES

What's the effective key length of Two-Key Triple-DES, for some (possibly several) reasonably well-defined and sensible definitions of effective key length, say assuming attack using ample chosen ...
3
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1answer
989 views

Do 2DES and 3DES2 have the same effective key length?

I am following the notes "Introduction to Modern Cryptography" by Bellare and Rogaway, and on the chapter about blockciphers there is the following claim (page 11 of https://cseweb.ucsd.edu/~mihir/...
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1answer
328 views

Can the key-complement property of DES be used against 3DES?

The comments in this recent question about the security of 3DES made me wonder if the key complement property of DES (which reduces its security by ~1 bit) can be used in the meet-in-the-middle attack ...
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1answer
93 views

Usage of 3DES for single block

I have a device, HASP, which has functionality to encrypt 8 byte data using 3DES in ECB mode, with three different keys, I am interested how secure is this? I know it might not be most secure, but how ...
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1answer
162 views

Creating a message authentication scheme

I have such situation. I have a device like dongle. But it has certain limitations. For example, it can only have implemented encryption and decryption functionality. The availability of ciphers ...
3
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1answer
236 views

Question on 3DES keys

The official NIST publication I saw says for federal applications 3DES with three keys should be used. I have such questions: what does it mean federal? Does it mean for industrial applications that ...
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1answer
2k views

Is a 4DES or 5DES system possible?

We know that 3DES is created with $E_{K_3}(D_{K_2}(E_{K_1}(m)))$ to extend DES's key length. Is it possible to extend it further by repeating this pattern? Perhaps using $E_{K_5}(D_{K_4}(E_{K_3}(D_{...
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0answers
180 views

Need help with PKCS#12 3 key triple des key expansion

I am trying to decrypt PKCS8-Shrouded Key Bag inside a PKCS#12 pfx file. The oid for the encrypted data is PbeWithSHAAnd3-KeyTripleDES CBC. Iteration count and salt has been provided within the pfx ...
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2answers
833 views

Different tools return different ciphertext value for equal input

I have a Luna G5 Safenet HSM and I want to encrypt a text file containing testtest with 3DES-ECB algorithm. So in the first step ...
2
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2answers
395 views

Why do 1st and 3rd key have to be the same in 2 key 3DES?

From this answer: However, that wasn't the only situation they had in mind; they also considered the case where someone implemented 2 key 3DES in hardware (which the first and last subkeys were ...
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2answers
710 views

Parity of an encrypted key

Does encrypting a double-length 3DES application key (that has an odd parity) under a double-length 3DES zone master key (also with an odd parity) affect the parity of the application key?
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1answer
1k views

Triple DES as cryptographic hash function

I need to generate a hash for a small piece of data (~50 bytes). I'd normally use MD5 or SHA but that's not available in the platform I'm programming for. Luckily, it provides Triple DES and I ...
2
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1answer
512 views

Output of using the same key in all 3 boxes of 3DES

I am trying to figure this one out: What would be the encrypted output for an input x if the same key K is used in all three boxes of 3DES? The encryption scheme for 3DES with three different keys, ...
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2answers
2k views

Triple-DES DUKPT CBC PIN variant vs Data variant

Does any know the difference between triple des dukpt decryption algorithm with PIN variant and Data variant? I have done Triple DES DUKPT PIN variant, which generate session key from KSN and BDK. ...
2
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1answer
940 views

What is the complexity for attacking 3DES in linear or differential cryptanalysis?

I know that 3DES is NOT vulnerable to DC , LC . But is it because the attacks requires too many input\output pairs ? Or because it's impossible ? (i.e requires more than 2^64 pair )
2
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2answers
422 views

3DES over Galois Counter Mode (GCM) for authenticated encryption

Is it possible to use DES or 3DES over Galois Counter Mode (GCM) to provide authenticated encryption? I haven't seen any implementation yet.
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2answers
10k views

Meet-in-the-Middle attack on 3DES [duplicate]

How can I apply the Meet-in-the-Middle attack to the 3DES algorithm, and why does the literature say that 3DES is more secure than DES?
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0answers
197 views

side channel attacks against TDES (compared to AES)

We all know AES has some pretty strong side channel attacks, some where (with a couple of hundred know plain- and ciphertext combinations) a key can be derived in a matter of minutes. Others may take ...
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1answer
17k views

Key sizes supported by 3DES

I read about 3DES encryption but I don't understand exactly what the specific meaning of key size is. For example I found that 3DES supports 64, 128, 192, and 256 bits key size. What are all the ...