2
votes
1answer
262 views

Find out which keying option is being used in Triple DES?

As far as I know, there are three standard options for the three keys $K_1$, $K_2$ and $K_3$ used by 3DES: Three distinct keys. The first and last key are equal: $K_1$ = $K_3$. Three equal keys: ...
1
vote
1answer
139 views

Regain 3DES ECB key, assuming I have both encrypted and decrypted text

Let's assume I've encrypted some text with some 24-byte key using 3DES in ECB mode. Is it possible to regain the key if I have both encrypted and decrypted text? (Excluding bruteforce.)
5
votes
1answer
106 views

Has a Two Key TDES encryption ever been successfully attacked?

Is there any known instance of a Two Key TDES ever being successfully attacked (in real life), when the key is used to encrypt less than $2^{20}$ words?
3
votes
2answers
194 views

Have these compositions of block ciphers the same security?

I'm interested by the compositions of the block cipher DES, instantiated with independent keys $k_1$, $k_2$ and $k_3$. Are these 3 compositions equivalent in terms of security? ...
3
votes
2answers
214 views

Composition of block ciphers and 3DES

There is some intriguing things about DES and 3DES. Now, I know that DES is weak and 3DES was an attempt to construct a more secure block-cipher from a deprecated one. Having this in mind, what ...
6
votes
1answer
4k views

Why is triple-DES using three different keys vulnerable to a meet-in-the-middle-attack?

Among other sources, this wikipedia entry states that triple DES using three seperate keys (k1, k2, k3) is vulnerable to meet-in-the-middle-attacks, while triple DES using only two keys (k1, k2, k1) ...
1
vote
1answer
4k views

c# Correct Triple Des Block Encryption Usage

I found the below code online, but in its original state, the encryption was not using any padding (Padding.None), and was encrypting in blocks of 8. I wasn't able to get this code to properly encrypt ...