Linked Questions

2
votes
1answer
394 views

Is there a truly safe signing algorithm?

After reading this question, I'm pretty shaken up. A determined attacker with $100 in loose change can crack any RSA key in a couple of hours. After believing that these algorithms would take millions ...
2
votes
1answer
162 views

Why is 128-bit considered “medium term” security?

Why is 128-bit encryption considered good enough for medium term security only? How is expected to be eventually broken? Quantum computing or brute force attack?
1
vote
1answer
149 views

Encryption using matrix transformations

I have been thinking lately about a block cipher which takes a block of bits and arranges them in a square matrix. Then defining transforms on submatrices of the square matrix to scramble the bits. ...
1
vote
1answer
68 views

Indeterminate Message Validity as a Noise Source in High Volume Channels

Question Rephrased: Does randomisation of valid and invalid messages in a high volume channel add security? Scheme: valid messages are identified by a pre-shared random number sequence and noise- ...
1
vote
1answer
1k views

Creating a random password based off of a prime number

So I am making an application that basically creates strings that must be encrypted before they are stored on a user's device. If the user blindly starts running the application without creating a ...
1
vote
1answer
2k views

Why is AES unbreakable?

Why is it said that AES is unbreakable? Brute force attacks would take years to crack it, so is it possible to crack it if the computational speed of machines increase in the following decade?
1
vote
1answer
1k views

Using HMAC-SHA256 with short passwords and sliced outputs for short-lived secure hashing

I don't have much background in cryptography, so forgive me if I'm using the wrong mathematical terms to explain my needs. Following this question, I learned that taking a random secret 16-bytes <...
0
votes
1answer
263 views

Perfect secrecy of block ciphers

Is it right that all block ciphers don't provide perfect secrecy like AES? If it's true, how can we prove that? If it's not true can you tell me a sample? Any reference or guidance would be ...
0
votes
1answer
61 views

Key generation algorithm based on bytes in a drive [closed]

I am a novice cyber security student and thought of a way to generate a random cryptographic key. The algorithm works as follows: Get the size (in bytes) of every file in a directory (drills down ...
0
votes
1answer
204 views

How can I study the math behind cryptography? [closed]

I am a junior in high school and I am currently studying algebra 2. Where can I go to learn about the mathematics behind cryptography? I have a very basic knowledge of cryptography, but I am really ...
-2
votes
1answer
338 views

SHA256 - Which is less impossible?

To generate every possible hash would be ... impractical. To work backwards from any given hash is also incredibly labor intensive. Of the two, which is less impossible? Why?
-4
votes
1answer
2k views

Is AES256 the most secure encryption algorithm available at the moment? [closed]

I have had to edit this question because it was too broad (sorry didn't realise that was not allowed...), so, lets go with: Is AES256 the most secure encryption algorithm available at the moment? If ...
1
vote
0answers
43 views

Maximum security strength in bits of ISAAC cipher?

Wikipedia claims key length can be very big in this cipher, so I assume it can offer a million bits of security provided entropy of key is the same? Of course I can SHA-256 hash the key to allow any ...
0
votes
0answers
39 views

Can we bound adversarial power in terms of total entropy in universe? [duplicate]

The strengths of various cryptographic primitives are often explained (though not defined) in terms of how long it would take to break under the current best known attacks. For example, apparently the ...
0
votes
0answers
224 views

What is the danger if a non-prime is chosen for RSA? [duplicate]

I was reading this question about generating primes for RSA keys. The answers point out that most implementations of of the algorithm use probabilistic prime-ness checking algorithms. The answer by @...

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