Sha256 is a hashing algorithm.

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58 views

SHA-256 VS SHA-512VL

Recently a friend of mine sent me a file accompanied by an SHA-512VL hash. My hashing tool GTKHash doesn't support this algorithm, and I've never heard of it. I asked my friend, and he pointed me to ...
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12 views

hash function notations and existing cryptographic hash algorithms [migrated]

I am implementing Role-based access control by referencing the paper Enforcing Role-Based Access Control for Secure Data Storage in the Cloud. In page 6, they have mentioned to choose hash functions ...
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1answer
19 views

How can SHA256-hashes as input to MD5 be revealed?

I know that you shouldn't use unsalted MD5 hashes of passwords in databases. But unfortunately, people do, see https://hashes.org/public.php. From this site I downloaded a file with passwords which ...
6
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1answer
123 views

Manually walking through the signature validation of a certificate

Since I am not too familiar with the Web of Trust and Public Key-Infrastructure I decided to learn about it by following the signing chain of a X.509 certificate issued to CN=*wikipedia.org (Serial ...
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1answer
46 views

SHA-256 Timestamp not recognized in windows 7 when dual signed

I wanted to dual sign my exe so that the XP and Vista users can use the software. But when i dual sign the exe with SHA1 and SHA256 timestamps, In windows7 only 1 timestamp is shown. To dual sign I ...
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1answer
76 views

Possible to take hash from know result and algorithm?

I am trying to build a casino site in PHP where users can play roulette. I found this algorithm that I want to use to "roll" numbers: <?php $secret = '...
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2answers
87 views

For high entropy credentials, is SHA256 hashing good enough?

Let's say I've got a database of high-entropy credentials (e.g. 256-bit random values) used as API keys by clients. I'd like to hash them in my database so that a database compromise doesn't allow an ...
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1answer
270 views

Is using “SHA-256 with RSA-2048 Encryption” a secure certificate hashing algorithm?

Is using "SHA-256 with RSA-2048 Encryption" a secure certificate hashing algorithm? I don't think it is. Two examples: nsa.gov [careers site] give.wfp.org
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1answer
80 views

Passwords processed on server side? [duplicate]

So while I was working on my personal project something struk me. When somebody creates an account on any web service/social media they provide their desired username and password,this is then ...
0
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1answer
65 views

Find SHA256 if I only have part of the string [closed]

I need to find the SHA256 hash of s string like this: "part1-part2". I know the SHA256 hash of part1 and I know what part2 represents, but I don't know what is the contents of part1. Is there any ...
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0answers
11 views

Is my current implementation of message signing on AVR sufficient and correct?

I am currently implementing a fairly simple signing library (for my personal use) to verify the identity of packets sent with the RF24Mesh library (using NRF24L01+) radios. Never made a flowchart but ...
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1answer
55 views

is it possible to find the original value of a hashed string, if you don't have the entire hash

I'm wondering if there is a faster way than bruteforcing to find the original contents of a string if you have/know: 60 % of the original string (30/50 characters) the amount of characters the ...
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1answer
72 views

Sum two SHA256 to get a SHA512 [closed]

I see this code in a web game SHA512(SeedServer + "|" + SeedUser) and I'm trying to reproduce this hash. I tried in PHP: <?php echo hash('SHA512', '...
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1answer
86 views

Store SHA256 in sql-server

I need to develop a payment gateway and I've just realized I need to store an HMAC_SHA256_V1 key for authentication operations. The way that this is done is: the browser calls a WCF service that ...
4
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1answer
145 views

How secure is my software for file encryption with AES-256?

I'm working on a project to build software for file encryption with AES in Java, it's operation is quite simple, but I was wondering if it is really safe. The program prompts the user for a ...
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1answer
51 views

which algorithm/hash can possibly encrypt and decrypt certain data regardless of size?

I have intercepted some data for which i don't know which algorithm has been used to encrypt this data, this data has been for sure encrypted before transmitting, to decrypt the data i should ...
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2answers
117 views

Possible to send password in plain text with SHA-256?

I just registered on a site where I had to specify sensitive information, eg. my card number. I got a confirmation mail where my password, the one I specified as my login password, was in plain text. ...
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1answer
43 views

Time of working generating hash with sha2

It is fragment of pseudocode algorithm SHA2 from wikipedia: break message into 512-bit chunks for each chunk create a 64-entry message schedule array w[0..63] of 32-bit words For me, it means ...
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7answers
10k views

Deprecation of SHA1 code signing certificates on Windows

I have been keenly following the issues with regards to Microsoft deprecating the use of SHA1 code-signing certificates for Windows executables (http://social.technet.microsoft.com/wiki/contents/...
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1answer
93 views

Can SHA1 certificate be used for SHA256 cipher?

I have two Windows 2008 R2 domain controllers configured with TLS 1.2. Both certificates are SHA1-RSA. I captured network traffic between two DCs while running LDAPS (LDP.EXE). It seems TLS 1.2 was ...
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1answer
40 views

Is D parameter of the RSA strong enough to be used as secret for HMAC calculation?

Short question: Is the D parameter of the RSA alghorithm crypthographically strong enough to be used as a secret key for generating SHA-256 hash value? Long question: I'm working on windows platform. ...
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2answers
136 views

Password manager's hash choices (scrypt + sha256)

Background information: Master password is a stateless password manager. It (deterministically) generates a password using a hash function, depending on your master password and the site name (also ...
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1answer
122 views

Do any browsers support Server Name Indication (SNI) but NOT SHA-2? [closed]

Yes, I know that SHA-2 signature validation is typically done by the operating system (with Mozilla Firefox/NSS and Chrome as of v39 being the exception).
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2answers
140 views

should I add a sha256 signature to an AES_256_CBC encrypted token?

currently I generate a token for an mobile app the way below. I decrypt the token to process the request and assess the user is logged in. I'm on TLS RSA 2048 bits connection. I was wondering if $...
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1answer
123 views

One-Time Pad authentication & Information-theoretic security

I'm trying to create a "Information Theoretically Secure" cryptosystem, inspired on the One-Time Pad. Now I'm facing the obstacle of authentication... How good is this solution (that uses the "Encrypt ...
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2answers
80 views

Is this explanation about how SSL Certificate Signatures work correct?

I was reviewing some information about SSL certificates and came across an explanation I believe to be incorrect. The explanation is of how signatures and hashing algorithms work in the context of ...
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1answer
45 views

Hashing Based Encryption

Let's say you take a 256 bit key and never use it to encrypt anything. You receive a message with a 16 character unique randomly generated salt pre-pended. You salt your key with the 16 character ...
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1answer
2k views

Creating an TLS certificate using keytool with SHA-256

I want to create a TLS certificate for my personal tomcat8 webserver on a Debian ARM server. I've done this before, using the following command: /usr/bin/keytool -genkey -alias tomcat -keyalg RSA -...
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6answers
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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 ...
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1answer
191 views

Understanding the HMAC Algorithm (SHA-256)

I've posted a related question on Stack Overflow, but I have a more general question about HMAC and SHA256. Let's say I want to generate an HMAC hash for a blank key and a blank message. The ...
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2answers
1k views

which hashing algorithm is better to use to store a password, sha256 or sha512? [duplicate]

which hashing algorithm is better to use to store a password, sha256 or sha512? I know that sha512 is more secure than sha256 but I was wondering if it has some disadvantages or it is completely ...
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1answer
43 views

Can a salt maintain pseudo-randomness after being modified?

TL;DR: How much can a function (such as the one below) modify an initially random string before that string becomes useless as a salt for password hashing? Is there a general rule? # Function ...
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1answer
74 views

Issue regarding installation of SHA256 scertificate

Can anyone help me with the installation of SHA256 certificate? I have generated the certificate perfectly but there seems to be an error below: Kindly let me know why am getting the exclamation ...
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1answer
347 views

What are the pros and cons of using sha256 to hash a password before passing it to bcrypt?

My apologies if this has already been asked. I recently became aware of the fact that bcrypt truncates passwords to 72 characters. Practically speaking my intuition is that this does not pose any ...
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2answers
306 views

Do I REALLY need to change my LastPass password?

Last weekend LastPass' network was compromised and that a list of email addresses along with the hashes of the master passwords were stolen. It is being recommended that LastPass users change their ...
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3answers
8k views

How secure are sha256 + salt hashes for password storage [duplicate]

I started reading about password hashing recently on multiple sites like this page on crackstation and others, and for what I have understood, I should avoid using hashing algorithms like md5 and sha1 ...
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1answer
1k views

Decrypting SHA-256 with known plain text

If i have a SHA-256 hash and I know what could be the crypted string is it possible to decode it faster? Lets say I know the string is formed like this : %d-%d-%d-%s %d being numbers from 1-25 %s ...
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1answer
985 views

Is there a benefit of using stateless JWT over SHA256 hash for API tokens?

Does it make sense to use stateless JWT (without persistent storage) over plain SHA256? Example scenario: User logs in User token generated as follows: a. JWT.encode(userId, 'secret') or b. SHA256(...
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27k views

What is the relationship between “SHA-2” and “SHA-256”

I'm confused on the difference between SHA-2 and SHA-256 and often hear them used interchangeably (which seems really wrong). I think SHA-2 a "family" of hash algorithms and SHA-256 a specific ...
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120 views

How does combining SHA256 with RIPE-MD160 compare to SHA256 + SHA-3?

Bitcoin stores its addresses as a combined SHA256 + RIPE-MD160 hash. Is it correct to assume this is done to prevent a failure in the algorithm? Since SHA3 was designed to be an alternative to SHA256,...
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2k views

SHA256 to text or MD5

I want to decrypt a sha256 to text. Is there a way other than bruteforcing to decrypt sha256? Like if I convert that SHA256 to MD5 and then try decrypting?I know its hard and the possible way for ...
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49 views

In DNSSec, are Delegation Signer Records always SHA-1?

I'm creating a RSA/SHA-512 Zone Signing Key and Key Signing Key at Dynect Managed DNS (corporate offering) The Delegation Signer Record that was created is SHA1. Should I be concerned about this?
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4answers
458 views

Getting password cracking time and byte storage from bruteforce?

I am stuck with this question, you can see it in the picture I have included below. PARTS (a and b) I know a-z will be 26^8, A-Z will be 26^8 guesses, and 0-9 will be 10^8 guesses. But I can't relate ...
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1answer
204 views

Could overlapping SHA256 hash begin to loop at some point?

I have a system that needs to send a key to the user. This key is used for validation after work and needs to be shown that we do not change it mid-work so we send to the user in the middle of work a ...
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1answer
189 views

Given Hash digest, calculating any random input

I understand that for a hash function there are an infinite amount of possible inputs that could produce a specific output. So if you're trying to find a specific input that created an output that ...
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1answer
154 views

If you can break this authentication system then you can break into my house

I'll preface this by saying I know approximately 0 about cyber-sec I've made a server that will allow smart phones to act as a remote control for my house (eg turn lights on/off and unlock doors). ...
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197 views

which memory hard hashing algorithm can equalize low-computational and high-computational power devices to utilize blockchain in the IoT?

Recently IBM and Microsoft showed their interest (IBM post, Microsoft post) in utilizing bitcoin's blockchain for internet of things (IoT) development. Let's assume that in close future the blockchain ...
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2k views

SHA256.DB30.com listing of email account

After searching a gmail account in Google I've found a result for the website SHA256.DB30.com. The page just shows the name of the gmail account and a list with major and minor hash. From my basic ...
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1answer
136 views

PKI - Security concerns when changing a certificate hash algorithm

Suppose I want to change the hash algorithm used for a certificate signature (ex: SHA1 to SHA2). Is it better to revoke the previous certificate and issue a new one with expected hash algorithm ? Or ...
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638 views

Corporate PKI - SHA1 deprecation

Here is the context. Suppose you have a corporate PKI with : AC_Root (offline in safe store - SHA1 signature) SubRootA and SubrootB (offline in safe store - SHA1 signature) SubSubRootC, SubSubRootD, ...