Questions tagged as 'criptografia'

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How exactly SHA-256 algorithm works [closed]

I did a search on the internet, but the results on the operation of the SHA-256 algorithm did not satisfy me, if anyone can help me I'll be grateful. Vlw.     
asked by 11.11.2015 / 12:11
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Encryption security in php [duplicate]

I know there are other things that help keep a system secure, but I would like to know specifically about one: information encryption. For example, the password is information that my projects always try to get encrypted in the bank. My que...
asked by 18.11.2015 / 15:01
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Password encryption

I have an Asp.Net MVC project and would like to securely store user passwords in the database. Home The goal is to create something that can not be easily decrypted in a few hours of brute force on a PC (I'm aware that with a little more effort...
asked by 15.09.2015 / 23:24
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Generate random random string in PHP

How to use the PHP language to generate a string, preferably with configurable size, random enough to be used in routines that handle encryption and that for security reasons can not be not too random? If you propose more than one solutio...
asked by 15.02.2014 / 20:20
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What is the difference between using password_default and password_bcrypt?

Searching for hash, I noticed that the second parameter of the password_hash function has two options, PASSWORD_DEFAULT and PASSWORD_BCRYPT , Exactly which of the two should I give preference to use? It should probably...
asked by 04.04.2017 / 15:40
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perfect forward secrecy, what is it?

I was reading a subject once quoted PFS and then I went to search, Wikipedia is weak on information about this, what is it? Is it like doing it? Please, I am a layman and I like examples, thank you in advance.     
asked by 15.02.2015 / 21:23
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Why is chr () vulnerable to a cache-timing attack and pack () not?

Out of curiosity I'm looking for and slowing down many things about cryptography and also looking for some pure PHP libraries, such as Sodium_Compat , for the sole reason that I understand a lot more of PHP compared to C, which is ideal for e...
asked by 19.02.2017 / 14:04
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How to Encrypt with the AES Algorithm using 128-192-256 keys in Java

I need to do an encryption with the AES algorithm by testing the runtime according to the sizes of the keys (128-192-256), but I can not find how to toggle the size of the key to be generated by the system, since my code returns that the key siz...
asked by 15.09.2015 / 21:47
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How to implement Diffie-Hellman in JavaScript?

I'm developing a web system where users can communicate with each other privately, without even the server having access to the communication content (ie end-to-end ). For this I intend to encrypt all the messages exchanged between them in th...
asked by 09.04.2015 / 05:02
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KEK (Key Encryption Key) what is it and how to use it correctly

I was reading "Cryptography and Security: The official guide to RSA" but I was limited to a few pages (if anyone has the PDF of this please share !!) and then I came across KEK and could not read more .. What is it and how do you use it corre...
asked by 06.05.2015 / 00:50