Questions tagged [3des]
A block cypher encryption algorithm built from applying three iterations of the original DES algorithm.
125 questions
0
votes
1
answer
640
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 ...
- 1
-1
votes
1
answer
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 ...
- 137
0
votes
1
answer
689
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?
- 29
1
vote
1
answer
4k
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) ...
1
vote
0
answers
164
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”.
- 11
46
votes
3
answers
40k
views
Is Triple DES still considered safe to use?
What it says on the tin. Is it still used in things like TLS?
- 3,705
-1
votes
2
answers
4k
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:
...
- 9
2
votes
1
answer
116
views
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?
- 711
2
votes
0
answers
292
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.
...
- 21
4
votes
2
answers
6k
views
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 ...
- 141
2
votes
0
answers
498
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
votes
1
answer
3k
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}...
- 395
0
votes
1
answer
1k
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 ...
- 29
3
votes
1
answer
1k
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 ...
1
vote
1
answer
2k
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 ...
- 121
3
votes
1
answer
319
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.
- 81
3
votes
1
answer
133
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, ...
6
votes
3
answers
35k
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 ...
- 181
2
votes
1
answer
1k
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 ...
- 25
-1
votes
1
answer
144
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 ...
- 101
2
votes
1
answer
5k
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 ...
- 43
1
vote
2
answers
2k
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 ...
- 11
4
votes
1
answer
3k
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 ...
- 145k
2
votes
2
answers
3k
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/...
- 177
2
votes
1
answer
1k
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 ...
- 32.4k
0
votes
1
answer
208
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 ...
user31507
0
votes
1
answer
345
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 ...
user31507
2
votes
1
answer
319
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 ...
user31507
3
votes
1
answer
4k
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_{...
- 2,429
1
vote
0
answers
341
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 ...
- 11
1
vote
2
answers
1k
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 ...
- 185
2
votes
2
answers
1k
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 ...
- 23
1
vote
2
answers
2k
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?
- 11
1
vote
1
answer
3k
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 ...
- 113
2
votes
1
answer
1k
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, ...
- 153
2
votes
2
answers
4k
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. ...
- 21
3
votes
1
answer
2k
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 )
- 203
2
votes
2
answers
910
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.
- 573
5
votes
2
answers
27k
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?
- 71
0
votes
0
answers
374
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 ...
- 976
5
votes
1
answer
31k
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 ...
- 51
3
votes
1
answer
1k
views
3DES Modes EED or EDE?
Can we use EED with 2 keys $(k_1, k_1, k_3)$ rather than EDE $(k_1, k_2, k_1)$? We measure the strength of DES by the effort (in terms of the number of tries) in finding some $k_1$ & $k_2$ to ...
0
votes
2
answers
483
views
Discrepancy with reported key size for EDE ciphers in Qualys SSL Labs
The following two cipher suites were reported by Qualys SSL Labs as being 112-bit:
SSL_CK_DES_192_EDE3_CBC_WITH_MD5
TLS_RSA_WITH_3DES_EDE_CBC_SHA
However, all other references I can find say that ...
- 3,567
2
votes
1
answer
1k
views
test vectors for 3DES seem to in fact be testing DES - not 3DES
NIST SP 800-20 Appendix A has what presumably are supposed to be test vectors for 3DES except almost all of the test vectors utilize 8-byte keys and not the 24-byte keys that 3DES is supposed to have. ...
- 2,959
2
votes
1
answer
689
views
OpenSSL des-ede3 not producing same output as test vector implies it should be
I'm encrypting one of the standard TDEA/3DES/DES-EDE test vectors with openssl:
...
- 2,959
1
vote
1
answer
2k
views
IPsec authentication and encryption lgorithms
I am looking for the implementation of IPsec security algorithms for both
authentication and Encryption.
Is there any open source implementation available for the same ?
And if someone supposed to ...
- 113
9
votes
1
answer
1k
views
Why should CAST5 and 3DES not be used for encrypting files over 4GB?
On https://www.gnupg.org/faq/gnupg-faq.html#define_cast, it says that
Like 3DES, its 64-bit block size means it should not be used to encrypt files larger than 4Gb in size…
How and why does the ...
- 93
3
votes
3
answers
382
views
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 ...
- 267
1
vote
1
answer
168
views
Process of dividing 168bit key into 56bit keys in TripleDES
I used TripleDES so many times but never thought about this. In TripleDES it requires 168bit ...
- 597
5
votes
1
answer
997
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 ...
- 597