A hash algorithm is a function which takes a variable size input and produces a fixed size output. The algorithm tries to make it difficult to predict the output for a given input, find two inputs with the same output, or reconstruct the input from the output.

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Securing passwords for REST Authentication

I'm developing a REST application using the Spring Framework, as as part of the requirements, we have to secure the different functions of the system to different user roles (pretty standard stuff). ...
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Are multiple applications of a salted Linux MD5 hash easier to break than one? [duplicate]

I hashed the same password a lot of times (approximatively 1000 times) using the salted Linux MD5 format. I want to know if it's easier to recover the clear password or not. Is there something that ...
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1answer
44 views

Would it matter if my miner was hashing random vs incremental values?

I'm working on my miner for my "game" site that's basically a pre-image attack from a hash posted online. You submit a hash input, it's hashed, and your score is the hamming distance (the number of ...
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1answer
648 views

Why store a salt along side the hashed password? [duplicate]

Understand the need to protection credentials with hashes that are expensive and to use cryptographically random salts. What I would like to understand is why you would store the salt along side the ...
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Using password hash as session ID?

For a rich client web app, on the server I need to verify that each call comes from a legally logged in user. Obviously user ID is not enough, because that's easy to guess. I have an idea I am ...
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2answers
831 views

Is it possible to salt the SHA1 or SHA256 hash function of OpenSSL?

I would like to salt the hash function of OpenSSL external, so that I can assign a salt on my own. Is that possible or is the hash function of OpenSSL alsways internal "salted"?
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2answers
591 views

Scrypt + Bcrypt = cascade hashing [duplicate]

I've read here that hashing with differents algorithms would be a good idea. Can you confirm that? In your experience, is it useful and safe? Does it entail any security holes?
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1answer
152 views

Challenge: How to find the secret key in homebrew MAC/keyed hash: sha1(key + cookie)?

I am trying to solve a security challenge on a website. Basically, the website computes sha1(key + cookie) to sign a cookie so that the user can't change it himself, and to accomplish the goal you ...
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BCrypt's 72-character limit and using it as a general digest algorithm

Goal: have token/cookie-based authentication that doesn't require keeping sessions on the server TL;DR: What, if any, is the accepted mechanism to work around the 72-character limitation of BCrypt? ...
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1answer
1k views

What difference between AES_128_GCM and AES_128 and AES_128_CBC ciphers?

I encountered AES_128_GCM cipher, tried to find it in specifications of TLS1.2 and nothing, any mention. Could some one explain the difference between AES_128, documented AES_128_CBC and this new kid ...
13
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Should password reset tokens be hashed when stored in a database?

Passwords are hashed so that if someone gains access to a database of passwords then they won't know what the actual passwords are and so they can't log in. If I can get a valid password reset token ...
33
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5answers
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https security - should password be hashed server-side or client-side?

I am building a web application which requires users to login. All communication goes through https. I am using bcrypt to hash passwords. I am facing a dilemma - I used to think it is safer to make a ...
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3answers
464 views

Strategy for updating stored passwords to more secure hash? [duplicate]

I know that we cannot update our hashed passwords without having the plain text password to re-hash. When a member logs in with login/password, we have the plain text, so that gives us an opportunity ...
5
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1answer
516 views

How can a system verify an online password using a phone keypad?

I phoned into a financial company's website, and it prompted me to key in my password on the phone keypad, converting the alphabetic characters to the corresponding digit, and special symbols to '*'. ...
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2answers
463 views

How to store/encrypt fingerprint?

Storing password is a no brainer : use a password hasher. But.. How do you proceed to store fingerprints securely on your server? Meaning that even if your server and all it's data is stolen, someone ...
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1answer
423 views

Extract Password Hashes from Active Directory LDAP

Currently we are working on a monthly internal security test which among other should contain a verification of the real password strength the users choose. For this reason I want to extract the ...
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32 views

Password storing using hashing only, encryption plus hash [duplicate]

I want to hash password before storing to database. I am not able to understand which approach will be suitable.For examples Hash plain password directly with SHA-1, SHA-256 etc and then store in DB. ...
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1answer
97 views

Ignoring collision and (second) pre-image resistance, what makes a cryptographic hash function strong?

With regards to resistance against dictionary and brute-force attacks to "crack" hashes containing passwords, what determines the resistance of a cryptographic hash function? Since collision ...
83
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2answers
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What are rainbow tables and how are they used?

Where can I find one? Is there a pot of gold at the end? How do I protect against them? From the Area51 proposal This question was IT Security Question of the Week. Read the Sep 09, 2011 blog ...
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2answers
872 views

What's the purpose of $LoginKey from the Ashley Madison leak?

According to this site Ashley Madison was keeping an insecure hash stored in their database using MD5, in addition to the far more secure bcrypt hash. This group used the MD5 hashes to quickly crack ...
17
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1answer
2k views

Password hashing : Using 2 salts [duplicate]

I'm developing an authentication service. I know the practice of generating a unique salt per user, stored in the DB with the hashed password, to prevent rainbow tables attacks. I just had the idea ...
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2answers
227 views

MD5 brute force on a faulty hash?

MD5 for passwords is considered insecure due to the ability to brute force and pick up the result. But what if I change some characters of an MD5 hash and I keep a record of that change so that ...
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1answer
288 views

SQLMAP --OS-SHELL error [closed]

root@kali:~# sqlmap -u http://www.a***********.com/info.php?id=2 --os-shell _ _ _| |_____ _ {1.0-dev-nongit-20150907} | -| . | | | .'| . | || |||||,| | || |_| ...
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1answer
30 views

Is the method of hardening the creation of a Cryptographically Generated Address (CGA) called hash extension

CGAs are sha1 hashes truncated to a 59 bit value. Along with a 3 bit security parameter they form a IPv6 address (more precisely the interface identifier). from wikipedia: The Sec parameter ...
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1answer
51 views

Risk associate with nonce and hash found in url

I have came across a url with nonce and hash in placed which is an account activation link sent via email. The example is as followed: ...
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2answers
127 views

activate user account through email

I see a lot of people say to hash for the token on email verification when dealing with member registration. I am wondering, if the email token is only to activate the account and nothing else, ...
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1answer
150 views

Is it possible to find out the salt of a MD5 hash?

I want to know whether it is possible to find out the salt of a MD5 hash? For instance we've got two MD5 hashes helloworld -> fc5e038d38a57032085441e7fe7010b0 goodbyeworld -> ...
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Are case-insensitive passwords a bad idea?

I recently discovered a service where the password was not case sensitive. I understand basic principles of encryption and hashing so I am a bit worried, is this service storing my password in plain ...
2
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3answers
408 views

Implications of hashing to UTF-8 in a cryptographic function

I know that most hash functions today use Base64 encoding for their functions, resulting in hashes that use a-Z and 0-9, and, sometimes, other special characters. This results in 62-76ish possible ...
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2answers
103 views

Is a random work factor an increase or decrease of security?

Assume you use a proven hashing algorithm, like bcrypt with a work factor of 10 or PBKDF2 with 10K iterations. Normally that's really secure already and would give enough security already for most ...
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1answer
65 views

How do I get the password knowing part of it and the length [closed]

I'm new to all this, I'm trying to use Hash Suite to find a password with a word + 2 numbers. I know what the word is but not the numbers but I also know the length of the passwords ... What do I have ...
0
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2answers
434 views

What current algorithms are considered (un)secure? [closed]

With the new release of Windows 10, Microsoft has given .NET, Javascript and C++ developers a whole new bunch of options for cryptographic algorithms. Where as the old .NET code only allowed AES and ...
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1answer
92 views

what is the most secure hash for virus definition databases in 2015?

I have been told, if I wanted to create virus signatures from infected files to use for detection in the future, I should be careful as some of them are prone to collision attacks?
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How does a hacker know how many times a password was hashed?

I've been reading a lot of questions about security and hash functions on this site and others. I am not an expert, just a curious mind and in my understanding the more iterations used to hash a ...
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Use of Nmap ssl/http md5 and SHA1 hashes

I have below stated result on of the system by map: 443/tcp open ssl/http Apache httpd 2.0.52 ((CentOS)) | http-methods: GET HEAD POST OPTIONS TRACE | Potentially risky methods: TRACE |_See ...
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2answers
140 views

What the most trustworthy way to demonstrate digital File Integrity?

I'm looking for ensure the integrity of uploaded files and demonstrate this integrity to a user. In my current scenario, a user sends multiple files in several different formats, these files are ...
3
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1answer
95 views

Can I safely and securely store hash(sessionId) in application logs?

I'm considering storing a hash of a user's session ID in our applications logs on each request. This would allow users sessions to be easily tracked back to actions in our logs. I understand that ...
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1answer
151 views

Random padding in hash functions

In this answer, it was recommended that you add random padding when hashing messages for a trusted timestamp, such as for predictions, in order to avoid dictionary and brute force attacks (at least ...
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1answer
42 views

Is there any problem using empty salts with PBDKF for this purpose?

The aim is to generate a secure key for symmetric encryption. I have a master password, from which I want to generate the key for symmetric encryption, in order to encrypt other passwords. The idea ...
3
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2answers
664 views

Determine salt length from hash

I am writing a basic Unix password cracker in Python that would work for MD5, SHA-1 and SHA512. I know that the salt in MD5 correspond to the 2 first chars of the encrypted password, and thus I ...
8
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199 views

Secure way to shorten a hash

If I want to save a hash of a certain number of bits, but my hashing algorithm gives me more bits than I need, then what is the safest way to shorten it? Should I: Just remove the first or last ...
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1answer
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Cracking Mysql 5 Hash using Hashcat

I am practicing cracking MYSQL5 hash using hash cat, however, for a reason or another, it finishes the cracking process too fast -within 30 seconds- without giving any results/errors back. I doubted ...
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0answers
49 views

Trying to figure out the hashtype of this digest-auth htpasswd file

Simple question for y'all as i'm having some trouble identifying the hash type of this from a http digest file that I have setup for rutorrent on a apache2 server. Here's an example of what it looks ...
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240 views

Storing Social Security Numbers in a Database

I'm developing an online application that needs the user's social security number. The application won't be processed on the web server so I'll be using an asymmetric key. So a compromised web server ...
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1answer
62 views

How to find an encryption algorithm between two hexadecimal numbers? [closed]

I have several numbers that are generated by a server. They are 16 digits long and are hexadecimal. I have no idea whether or not any salting or hashing techniques were used. Can I find the encryption ...
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3answers
55 views

Hashing Algorithms Costs vs Sleep

I understand most of the concepts behind hashing password but this one still escapes me. I understand that you want the hash to take some time ( a couple milliseconds) so the attacker can't ...
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5answers
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The AES Crypt implementation hashes a password 8192 times to generate the key. Is this necessary?

I'm considering encrypting some small files (hundreds of kb apiece) using the AES Crypt reference implementation. Looking at the source, it seems that the encryption key is derived from the IV and the ...
27
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5answers
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Doesn't hashing passwords server side mean a compromised website could leave passwords vulnerable?

So the traffic is encrypted to a website so the password is safe during transmission and also if the website is hacked then the database only contains hashes. But couldn't the hacker create a server ...
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2answers
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Double hashing using a relatively new hash and a old, tested one

Note: I am relatively new to cryptography in general, so please point out if I make any misconception here. I heard that you should always use well known crypto/hash functions, that have already been ...
2
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4answers
116 views

Is there a security advantage towards hashing a password on the server? [duplicate]

I'm working on an authentification system. Now in this system the user logs in and sends a hashed password to the server. Is this enough or do I have to rehash the password again? So basically is ...