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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Can client-side hashing improve after-the-fact security in response to password leaks?

Several questions on this site address client-side password hashing, and none of them admit to any security benefit beyond protecting other sites the user might use the same password for. However, ...
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2answers
106 views

Strength of WPA passwords

How long would it take to crack an 8 letter (latin alphabet, lowercase) password of a WPA PSK network? Is it in reach of a single PC running hashCat?
2
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1answer
157 views

Encrypting data before sending to SaaS tool and decrypting on browser view

I'd like to send data to a SaaS tool, where the data is stored in the cloud. I'll use Google Analytics as an example, but it applies to any similar service. Google Analytics does not allow you to ...
2
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1answer
2k views

Rainbow tables/hash tables versus WPA/WPA2

In Wi-Fi penetration testing, is it possible to use rainbow tables/hash tables on WPA/WPA2 networks? Is there an advantage of one over the other? Where would one get said tables or can they be ...
1
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1answer
31 views

PHP BLENC extension security concern

PHP BLENC is a extension that allows PHP developer encrypt their code, protect their ideas and avoid illegal copy. Although BLENC allow developer to define the main encryption key in source(in the ...
1
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1answer
78 views

Protecting email addresses if their hashes are publicly avaliable

I am working on a project, where user email address hashes will be available publicly, and I need to prevent them from being quickly discovered by spammers. The main idea of the undertaking is to ...
0
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1answer
38 views

Re-sign Certificate Using Different Hashing Algorithm

Consider a certificate used by a Certification Authority. This is currently hashed using SHA-1. I'd like to keep the same public/private key for this, but hash it using SHA-256. By hash it I mean hash ...
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1answer
385 views

Why not use md5 auth mechanisms for IMAP over TLS?

I'm using Dovecot for IMAP connections. I've read a lot of tutorials on how to set up Dovecot, and a lot of them said to only allow: auth_mechanisms = plain login Why should I not allow *-md5 ...
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1answer
93 views

How to identify this hash?

I have one hash, I know its value, but not its type. Here is it: 6dfb036bf703d75f9bc8219ba1224d876783fa61 I tried something like php -r "echo sha1('abc');", but it gave me another value, so this ...
10
votes
0answers
226 views

How does SHA3 (Keccak & SHAKE) compare to SHA2? Should I use non-SHAKE parameters?

Keccak is the winner of the SHA3 competition. Since Keccak is highly customizable (presumably for security/memory/time/speed tradeoffs) there does seem to be some controversy around how Keccak ...
8
votes
0answers
387 views

Naive implementation of Rainbow Table and/or Hellman's trade-off

This question is the same one I asked here. Since I haven't got any response or even a comment I will post it here as well. Is there any naive implementation of Hellman's cryptanalytic time memory ...
4
votes
0answers
211 views

OpenSSL 0.9.6a PRNG algorithm weakness: How to exploit?

I saw an OpenSSL security advisory for Openssl 0.9.6a Recently a cryptographic flaw in OpenSSL's built-in pseudo-random number generator (PRNG) was pointed out to us by Markku-Juhani O. Saarinen ...
3
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0answers
86 views

How far should I go in protecting a user's SMBIOS UUID?

My server will be receiving data from several hundreds of computers. As part of keeping track of which computer sent what, I will be fingerprinting the hardware and keeping the results in my database. ...
3
votes
0answers
166 views

Login details security using salt and hash, and a login role in postgresql

I am coding up the security for a website in express.js and postgresql database. Now I have been reading about salting and hashing and I have the code set up with pdkdf2 using the crypto module, but ...
2
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0answers
50 views

Reviews of Argon2

I am not a security guy but just curious about the things here. I have seen several people in various answers here talked about the password hashing competition. Now that the winner is announced, I ...
2
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0answers
45 views

Is the 64-bits length of the original string padded as well in the MD5 hashfunction?

So, for example I have a string which binary value is exactly 512 - 64 bits long, so the binary conversion of the string does not have to be padded. So that means I have a string of 56 chars. The ...
2
votes
0answers
78 views

CMS/PKCS#7: specifying signatureAlgorithm with digest?

I'm confused about algorithm selection for Cryptographic Message Syntax (a.k.a. CMS, PKCS#7) signed objects (RFC5652 Section 5.1). The SignerInfo structure (RFC5652 Section 5.3) has two separate ...
2
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0answers
95 views

Is there any merit to the RFC 3414 (SNMPv3 User Security Model) password-to-key method?

RFC 3414 (published 2002) specifies a method of generating keys based on password in its Appendix, which essentially takes any "passphrase", and keeps on repeating it until there is a 1MB string, at ...
2
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0answers
513 views

How do I convert from this weird John/Asleap format to lc (for HashCat)?

I'm trying to setup a system for pen-testing. I'm using the FreeRadius-WPE patch to collect Challenges/Requests from people who connect to my spoofed AP instead of the actual network. Here is the ...
1
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0answers
45 views

SHA1 and SHA256 initial digest to start from

Let's say I have: C = A + B where A and B contain strings and the plus sign means concatenation. I already hashed A with SHA1 and SHA256 and got a digests. I forget what the original A string was, but ...
1
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0answers
41 views

trapdoor information with hash functions

I have been playing with an idea for the past few days. I have been unable to find information on here or crypto.stackexchange about using trapdoor information in the input to a hash function. ...
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0answers
44 views

Token-based authentication for specific requirement

We have the following requirement for creating a token in .NET to be used in providing a challenge token and an actual authentication (auth) token. The auth token will then be used to authenticated ...
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0answers
74 views

Securely storing users PIN on Android with fingerprint authentication

I am have an Android app where the user can enter a pin specific to a particular phone to save them entering the full password. I'm now looking at the new fingerprint reader API on Android M where I ...
1
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0answers
39 views

Key stretching approaches

I've seen that a number of key stretching algorithms and they involved increasing the number of operations needed to compute the key(i.e. the number of rounds within a hash function). But, I wonder if ...
1
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0answers
239 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 ...
1
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0answers
161 views

John The Ripper and OpenCL on AMD FirePro

Trying to work with John 1.8.0 Jumbo 1 I noticed that OpenCL won't work for me. I used autoconfig (meaning configure and build with the option to enable OpenMPI) in order to build JTR for my Mac Pro. ...
1
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0answers
176 views

PKCS#7 signed data structure in signed PDF document

Is it mandatory to include PKCS#7 data (OID 1.2.840.113549.1.7.1) octet string into the sequence of PKCS#7 signed data? I mean if you want to sign PDF, you are basically adding PKCS#7 container ...
1
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0answers
104 views

Breaking it gently

Let's say I've found a fundamental error with mathematics of a security package. For example, let's say I've found something similar to the Pollard’s \rho-1 algorithm that renders some of the RSA keys ...
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0answers
1k views

Brute-Force/Dictionary attack against encypted file using PBKDF2 key derivation

I have been following this very useful post by Thomas. My use case is slightly different. I am developing a mobile application which requires some sensitive data to be stored on the device in a SQLite ...
1
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0answers
182 views

How does an attacker authenticate to a service using just the hash of the user (after performing a pth attack)

Let's say the attacker got the username and the password's hash. How can he use it when authenticating to some service in its domain with NTLM , for example? How can he send the request as the ...
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0answers
83 views

Does whosthere.exe of pth toolkit have to run with administrative rights?

To see the users that are connected to the machine and they're pass hashes with Whosthere.exe, do I have to run it as an administrator?
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0answers
211 views

Persistent login by hashing password hash

It seems that persistent logins are technically the same as storing a password on the client, and therefore should be avoided whenever possible. However, real life users would be unhappy with having ...
0
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0answers
8 views

Applocker rules Publisher vs hash

I'm interested in deploying application white-listing for a large scale environment by using the Windows Server built-in AppLocker mechanism. There is no Internet connection to the environment. My ...
0
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0answers
23 views

Malicious node in distributed hash table (Tor)

I'm thinking about the DHT in Tor that is used to look up hidden services. Namely, if you were running a node in the Tor DHT system, 1) Could you realise that you were storing the data for a nasty ...
0
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0answers
32 views

Generation of the primes p,q and g for DSA using an Hash Function in OpenSSL

We can generate primes p,q and g for DSA in OpenSSL by using command: openssl dsaparam -text -out dsaparam.pem 1024 Is it possible to generate primes p , q and g using an Hash Function in OpenSSL ...
0
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0answers
58 views

Hashing Identifiers to Create Pseudonyms

I'm wanting to share datasets between two organisations in a pseudonymised way such that they link together via mutual entities (e.g. people) but so that the entities cannot be identified. E.g.: ...
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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 ...
0
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0answers
532 views

Line Length Exception in hashcat

I'm very new to cracking a password so sorry if I sound stupid. I am trying to get my admin password from my second PC (I lost it). I did find the SAM file with kali linux and with bkhive and samdump ...
0
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0answers
87 views

What is the format of PDF hash?

When I use a tool like pdf2john.py from John The Ripper on an encrypted PDF, it gives me an output like: ...
0
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0answers
54 views

Designing a security system for road pricing

It's my first semester with Information Security and I still feel a little lost. Sorry in advance for stupid mistakes I may have made. the examples in round brackets below are my own ideas, wrote ...
0
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0answers
70 views

Understanding the application of hashes, HMACs, and KDFs

I think that I understand the right application cases for the following crypto functions, but I'd like to confirm my understanding and also propagate the safe use of crypto throughout the intertubes. ...
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0answers
46 views

Retrieve original password from hashed password (without salt)

Assume the victim is a who did not use salt to hash the stored passwords. Somehow let's say I steal some passwords from the database. As an attacker, is it a good a approach to create a dictionary ...