Linked Questions

-4
votes
1answer
97 views

Binary Numbers converted to Hexadecimal private key [closed]

Couldn't you use brute force to guess someone’s binary number because it's 1 or 0 - 256 times then just keep switching 1's and 0's around- which then can be converted hexadecimal to guess their ...
5
votes
2answers
4k views

Do you need more than 128-bit entropy?

UUID uses 128-bit numbers. Currently it is not feasible to randomly produce two UUIDs that are the same. Does that mean 128 bits of entropy is suitable for all cryptographic operations? I would ...
5
votes
1answer
7k views

Is there a maximum allowed key size in the USA?

I've heard that using encryption outside military use has been illegal for a long time in the USA. However, I've also heard that when the regulation was updated, limits were put on encryption strength ...
15
votes
2answers
22k views

Why does Google prefer ECDHE-RSA-AES128-GCM-SHA256?

I want to configure my new mail server secure as possible and wondering about the used cipher while connecting to Googles SMTP server. I'm curious why they prefer the cipher ECDHE-RSA-AES128-GCM-...
1
vote
1answer
317 views

KeePassXC & Yubikey HMAC-SHA-1 vs 40+ Character Password

Looking at the implementation of the Yubikey 4 HMAC-SHA1 mode for KeePassXC, I want to know: Isn't the HMAC-SHA1 challenge response less secure than a 40+ character password? From what I know, the ...
11
votes
2answers
1k views

Unseen.is encryption claims revisited with their proprietary, patented “xAES” algorithm

I had asked last year about the encryption claims by the web service called https://unseen.is. The very same service that had claims of "beyond army level encryption", "4096 bit keys" etc. This is the ...
88
votes
4answers
18k views

Will quantum computers render AES obsolete?

This is a spin off from: Use multiple computers for faster brute force Here's at least one source which says that quantum computers are on the way to being able to break RSA in the not too distant ...
26
votes
7answers
3k views

Is sha1sum still secure for downloadable software packages signature?

We use sha1sum to calculate SHA-1 hash value of our packages. Clarification about the usage: We distribute some software packages, and we want users to be able to check that what they downloaded is ...
12
votes
3answers
3k views

ProtonMail security concerns

This TED talk brought me here. First of all, to those who created ProtonMail: Nice job!!. Regardless of what people say, it's definitely a big step forward from tradition options like Hotmail, Gmail ...
1
vote
2answers
365 views

Are the Microsoft Windows images found on the internet safe?

Microsoft has stopped offering the Windows images for download. It is now only possible to get the image if one has a key of a retail version of the corresponding OS. The question is now, whether the ...
17
votes
4answers
33k views

What do key size and block size mean in cryptography?

Can some one simply explain the meanings and the difference between symmetric key and block size. Why 64 block size not safe any more and they increase it to 128 (AES,...,Serpent)? And what about key ...
8
votes
4answers
9k views

Calculate time taken to break AES key

A 256 bit AES key is required to be broken using the brute force method on a 2GHz computer. How long would it take to break the key in the best case and in the worst case situations? Assume that 1000 ...
28
votes
3answers
5k views

Use multiple computers for faster brute force [duplicate]

I've watched Mr. Robot lately and can't stop thinking why it was so hard to decrypt files encrypted using AES encryption with a 256-bit key. Let us say the only method to find the key is through brute ...
0
votes
1answer
215 views

PHP - Does password_hash/Argon2i effectively truncate passwords after certain length?

If I'm not wrong, by default PHP's password_hash with PASSWORD_ARGON2I outputs a 43-character alphanumeric hash among other things. While this means that simple passwords that are shorter than 43 ...
2
votes
0answers
85 views

How easily could a global network of machines break cryptography? [closed]

Suppose the NSA through legal means, or a malware group through illegal means has access to enormous computational resources via a backdoor into all Microsoft Windows machines (or some significant ...

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