Most voted "hash" questions
A hash function is any well-defined procedure or mathematical function that converts a large amount of data to a small data, usually a single integer. This tag should be used for more general hash questions; questions about hash classes should use the specific tag.
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384
votes9
answers31327
viewsHow to hash passwords safely?
If I do the hash of passwords before storing them in my database is enough to prevent them from being retrieved by someone? I’m just talking about the recovery directly from the database and not any…
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45
votes3
answers4342
viewsWhat is the difference between encryption, encryption and hash calculation?
I see a lot of confusion on the site about the terms. In the context of security of data what would be encoding, Encrypting and hashing and in which contexts each should be used? In particular, does…
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18
votes2
answers5391
viewsWhat is the HMAC?
When working on a project that uses sha256 and security keys, I came across the term hmac. I’m still not quite sure what this is about, and I’d like to understand a little more. I have the following…
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14
votes1
answer356
viewsWhat would be a good hash calculation algorithm to use in a scattering table?
In the question Why String hashcode() in Java uses 31 as multiplier? There is talk of the use of the number 31 as a multiplier. There has been a controversy about the motivation of this number. In…
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13
votes2
answers16707
viewsHow do the SHA family hash algorithms work?
I would like to understand how the hash algorithms of the SHA family work (Secure Hash Algorithm), such as the SHA-1, SHA-2, SHA-3, and understand the differences between them. I seek didactic…
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12
votes1
answer13778
viewsHow does the MD5 hash algorithm work?
I would like to understand how the hash algorithm works MD5 (Message-Digest Algorithm 5). He is considered safe? I seek didactic answers, which make me understand the processes used by this…
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12
votes2
answers1508
viewsChoice of hash generation method in PHP
My doubt started when I decided to re-examine the method I was using to get the user’s password and store it in the database. After reading that one, that one and that one questions here on the…
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12
votes1
answer605
viewsWhat is required to achieve maximum entropy?
I’ve been studying a little bit about random numbers and hashes, Yet something somehow still confuses me. In several groups related to cryptography I read about people talking about the addiction of…
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11
votes3
answers828
viewsHow do I generate a hash in the client-side?
I’m researching ways to create a login system with a secure encryption that doesn’t weigh down the server. Taking as an example that answer I am searching for a way to make client-side encryption,…
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8
votes2
answers280
viewsTrigger an action when a hash is found in the URL
The idea is to start an animation when a hash is found in the URL. Example Taking the example of a page whose navigation works by hashing: <nav> <ul> <li><a…
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8
votes1
answer350
viewsHow to use Salts and hashs with PHP?
Following people, I have to make a system of registration and login of users, but wanted to increase the security of this system using Salts in passwords, someone could show me a simple example…
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8
votes3
answers953
viewsHow do you relate the hash which is also called the python dictionary to the encryption hash function?
I would like to understand how the encryption 'hash' function (in which passwords for example are encrypted) relates, with the key-value hash in programming (also known as 'dictionary' in Python for…
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8
votes2
answers334
viewsWhat is a Murmurhash?
I saw that is being programmed for next version of PHP 8.1 the implementation of Murmurhash. I had never heard of it. I would like to know what it is.…
hashasked 3 years, 6 months ago Wallace Maxters 102,340 -
7
votes2
answers1074
viewsIs it efficient to check file modifications by Hash?
Setting I need to implement a file change check between 2 points in my application. *¹ Point 1 - Server - I have a folder where are some product images; Point 2 - Mobile Device - I have a catalog…
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7
votes1
answer182
viewsIs it possible to use MD6 in C#?
Speaking of hash, it is possible to use MD6 in C#? Someone would have an example of the use in a simple string? In my research I found nothing very objective.
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7
votes1
answer3146
viewsCan the MD5 hash repeat for different passwords causing collision?
A co-worker made a System in Java that encounters collisions in a series of MD5 hash passwords. But he did not stop to analyze the results, he made only a statement that they exist. Only that I…
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7
votes2
answers339
viewsWhy does String hashcode() in Java use 31 as a multiplier?
In Java, the code hash for an object String is computed as s[0]*31^(n-1) + s[1]*31^(n-2) + ... + s[n-1] using integer arithmetic, where s[i] is the i-nth character of the string, n is the string…
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6
votes4
answers2718
viewsGenerate sequential Ids without losing the sequence
For Identity do not want, because it breaks the sequence if something happens. Max() + 1, I find it very vulnerable and slow when you have a lot of records. So I ask you, is there a way that someone…
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6
votes3
answers11827
viewsUse list as dictionary value using Python append() method
I have some python dictionary, and I want to assign a list as a value for each dictionary key, but I need to use the append() method to add elements, but after adding the elements to the list, the…
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6
votes0
answers906
viewsHow exactly the SHA-256 algorithm works
I did a search on the internet, but the results on how the algorithm works SHA-256 have not satisfied me, if anyone can help me I will be grateful. Vlw.
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6
votes2
answers10977
viewsSDK Command Facebook Android - Key hash
I’m doing the tutorial on SDK of Facebook for Android and I didn’t understand this part, which talks about hashes key to development environments. Commando: keytool -exportcert -alias…
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6
votes3
answers284
viewsWhat should I observe when creating a hash code?
Still talking about the reply about hash code it was not clear what should be observed to produce good hash codes. I understood that it needs to be a number that doesn’t generate a lot of…
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5
votes2
answers705
viewsHow to calculate hash?
How do I calculate the hash of a torrent file with PHP? I’ve used the class BEncoded and it worked, but I wanted to know how it works.
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5
votes3
answers626
viewsHow does php guarantee a single session_id?
Which algorithm used to secure a single session_id()? I wanted to know what the creation and verification is like to ensure that such an ID does not collide with an existing one? I need to create…
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5
votes1
answer423
viewsWhat is the hash generation algorithm that Laravel uses?
By default Laravel already comes with a pre-ready authentication system, however, someone would know tell me what the algorithm is default that this framework use for generation of hash and what…
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5
votes1
answer251
viewsDoes it make sense to store the salt of a password with the hash itself?
Looking at tables in a database of a certain product, I came across a structure similar to this: [LocalUsers] UserId Integer PasswordHash Byte[] Salt Byte[] If an intruder gets this list, it’s…
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5
votes1
answer276
viewsHow to convert Python encryption to PHP?
I wonder if it is possible to convert this encryption to the PHP language, I need to convert the passwords that were generated to be accepted in my Login system on the site, but I do not know how to…
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5
votes2
answers139
viewsCan hashes be different for the same bytes?
I’ve found a flaw or I can’t deal with hashes. I have two bytes arrays random, one generated by an algorithm and one original. I am trying to make the algorithm EXACTLY the same as the original.…
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4
votes2
answers252
viewsInterpret and direct with URL that after domain contains a hash
I am creating a rule for interpreting addresses that after the domain begin with # followed by numbers or followed by letters whose rule should only be read if there is no file or directory matching…
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4
votes2
answers962
viewsWhat is the difference between Encoding, Encryption and Hashing?
I’d like to understand the difference between Encoding, Encryption and Hashing and also examples of when using one or the other.
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4
votes1
answer366
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4
votes1
answer665
viewsMessagedigest and hash class with MD5 in java
I’m testing the creation of Hash using this class, and I’ve seen on several websites, including on Soen, the use of snippets similar to the following to create hashs using md5, but without much…
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4
votes1
answer145
viewsGenerate XML content HASH in SQL
Is there a way to generate the hash of a XML beyond the function master.sys.fn_repl_hash_binary? Currently this is my implementation, however, I do not know if it is the only way to do. --Preparação…
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4
votes1
answer4728
viewsHow to transform source code into digital hash summary?
For registration of a software, it is requested: Perform the transformation of the technical documentation (source code) into digital hash summary; the INPI documentation also states: [...]The hash…
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4
votes1
answer1099
viewsHash, Object or Dictionary?
I have been studying python and ruby and have seen that several other languages as well as these two make use of different terminologies to determine a ' Json object. var objeto = { 'name' : 'Darth…
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4
votes1
answer1005
viewsBest Way to Use AES Encryption
Guys, let’s say I’m working on a system where the encryption key is derived from the user’s password (something like what Keepass does), in which case I have three questions: What algorithm to use…
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4
votes1
answer474
viewsCode to generate user password hash in Oracle 10G with C#?
I need to authenticate users in a web application in the Oracle 10g database, but the credentials are native to the database by running an Oracle Forms application already, and we would like to keep…
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3
votes2
answers654
viewsProblem decrypting hash in Base64
I was reading about an apache rule for validating permissions to access files/directories, and saw that the default file that reads the user and password was: usuário:senha (sendo a senha em…
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3
votes2
answers2877
viewsHow to apply password_hash for SELECT, INSERT and UPDATE?
I know the password_hash works like this: string password_hash ( string $password , integer $algo [, array $options ] ) 1 - But I wonder how I can apply password_hash in such cases: $check =…
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3
votes1
answer89
viewsWhich hash algorithms are already embedded in PHP?
Recently I was looking for hash algorithms that were not known md5, sha1 and sha2, and that generate smaller hashs than those cited. That’s when I found myself thinking, how can I know which hash…
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3
votes2
answers69
viewsGive same value independent of the order
I needed to somehow generate a "hash" from a string but that the same hash is obtained independent of the order of the two strings 1234+4321 = asdfghjkl 4321+1234 = asdfghjkl this is possible with…
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3
votes1
answer94
viewsWhat is the probability of the Crc32b hash repeating?
What is the probability of hash Crc32b repeat itself? For example, two different strings return the same code: echo hash('crc32b', 'Teste');
hashasked 6 years, 7 months ago Silvio Andorinha 8,394 -
3
votes1
answer140
viewsUsing Hash, without adding a Salt string to the password, can make the password vulnerable?
A little while ago I needed to figure out which hash had been used to save passwords in the bank so that they were not directly saved according to what the user launches at the time of their…
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3
votes1
answer4431
viewsHow to remove a line in python txt file
Good evening, I am having problems while removing a line from a txt file, the deleting function of the code is responsible for removing a user, however while trying to remove the entire file is…
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2
votes1
answer117
viewsIs it possible to use Query String and Hash at the same time?
I am developing a one-page site only using the hash’s html to scroll the page until the id specified, but the need to use also a query string with php, but now every time I try to use both of them…
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2
votes1
answer735
viewspassword_hash or crypt, which brings more security?
I don’t know much about hash and security, I found two functional functions and I couldn’t figure out what the difference would be between them and therefore which is the safest one to save and…
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2
votes1
answer142
viewsAccessing variables dynamically in C language
I understand that it is possible to access variables dynamically in Javasscript, but to do this in C, I can’t find anywhere. Follow the code in Javascript: var n1,n2,n3,n4,n5; n1 = n2 = n3 = n4 = n5…
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2
votes1
answer207
viewsTable Hash with quadratic method
I am implementing a hash table with quadratic scanning method. My question is about the position 0 of the vector used for table implementation. Follow the code below: public boolean inserir(Pessoa…
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2
votes2
answers251
viewsPython code using HMAC library
I’m doing a paper on cryptography for college using HMAC along with SHA256, and I’d like to understand what this code does on each line, I’m a little confused. #!/usr/bin/env python3 import hashlib…
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2
votes2
answers97
viewsLoop in Constructor c#
I’m trying to set mine Senha using the md5, but there is a loop at settar. public class Usuario { public int ID { get; set; } [Required] public string Nome { get; set; } [Required] public string…