Questions tagged [3des]

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

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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 ...
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1answer
25 views

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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2answers
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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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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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1answer
577 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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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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2answers
1k views

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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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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1answer
107 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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1answer
71 views

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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1answer
723 views

No of keys used in Triple DES Algorithm

I am studying Triple DES. I have got two basic questions. One, why are we following a sequence like encrypt(decrypt(encrypt)); what is the problem using a sequence encrypt(encrypt(encrypt))? Second,...
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1answer
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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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1answer
23 views

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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2answers
184 views

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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1answer
56 views

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
881 views

Is TripleDES 168bit vulnerable to Differential Cryptanalysis?

I was reading this paper. In the table-1 of the paper it says TripleDES (showing both 128bit and 168bit keysize) is vulnerable to Differential Cryptanalysis. It also says that AES (showing all three ...
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2answers
135 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
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What is U2FsdGVkX1?

Using CryptoJS 3.1 I noticed that using 3Des, the encrypted message always start with U2FsdGVkX1 Why is the first part of the encryption always the same? What information does this hold and how ...
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1answer
188 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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1answer
174 views

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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2answers
176 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
123 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
93 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
257 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
215 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
216 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
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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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1answer
401 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
609 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
11k 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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1answer
750 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
2k 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
402 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
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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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2answers
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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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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
591 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 ...
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2answers
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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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2answers
13k 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
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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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0answers
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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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1answer
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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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1answer
636 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 ...
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3answers
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Does 3-DES take approximately the same time to encrypt 1B and 1KB?

I am using 3-DES to encrypt some data in Java. I decided to run some tests and plot some graphics to decide how to optimally pack data for its encryption (see how encryption/decryption time behave ...
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1answer
985 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 ...
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2answers
4k views

How can 3DES encryption use decryption in the middle step?

I have been reading about the 3DES algorithm and I cannot understand one part. In 3DES we do following operation: $$C=E[K_3,D[K_2,E[K_1,P]]].$$ Where $C$ is ciphertext, $P$ is plaintext, $E$ is DES ...
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1answer
250 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.
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1answer
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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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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. ...
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1answer
794 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 ...