Linked Questions

10
votes
3answers
21k views

128 bit 3DES Key and AES Key: what's the difference?

Apologies if this is really basic but I couldn't find the answer to this. I have heard some Info Sec colleagues talking about creating an AES key in preference to a DES or 3DES key but I don't know ...
1
vote
2answers
939 views

Converting normal alphabets to 64 bit plain text

How can I convert a normal alphabetical text (say hi) to a 64 bit or 128 bit binary digit input for DES?
2
votes
4answers
370 views

Multi Factor Encryption?

I got an alert last night to the keywords above and was curious, so took a look at the tor site flagged which is the following one: http://nsrz5iogimqwgeax3clpp6hvfy6viom2woy7dghgxes4sqk63r7svoqd....
4
votes
2answers
3k 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 ($2^{112}$)?
3
votes
3answers
373 views

How was PC2 designed?

I am trying to understand DES. Can anyone explain the table given in one of the answer DES Key Schedule Algorithm. My question is from where the first entry of Ks comes from. i.e ...
1
vote
1answer
294 views

Parity checking on DES key if using ASCII chars

This is my first question here, so if I ask it to the wrong group or otherwise infringing the (written or unwritten) rules of the community, please bear with me. My problem is this: In an exercise in ...
0
votes
1answer
255 views

How to find a triple of keys that maps plaintext to given cipherext using EDE

What is a practical method for for finding a triple of keys that maps a given plaintext to a given ciphertext using EDE? I think this requires something similar to a man-in-the-middle attack...
5
votes
0answers
181 views

aside from DES has the NSA ever strengthened algorithms?

When DES was originally developed, the NSA changed the s-boxes. For decades people thought that their changes introduced a backdoor but then it was discovered that their changes actually strengthened ...
1
vote
1answer
103 views

Why isn't data encrypted with mutiple ciphers?

Why isn't data encrypted with multiple uncompromised (so far) ciphers? Feel free to answer for a single private key for both and separate private keys. For example, encrypting data with TwoFish and ...
0
votes
1answer
79 views

How to perform the initial permutations 64-Bit DES to derive $K$?

Perform DES encryption on the first 64-bit plaintext only, what are these 0's and 1's? Do they mean that I need to use this ...