Questions tagged [algorithm]
Algorithm is a set of step-by-step operations to be performed including calculations, data processing, and automated reasoning.
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IIS Crypto 3.2 not getting rid of Diffie-Hellman algorithms of less than 2048-bits
I'm trying to stop a server using Diffie Hellman key exchanges of less than 2048 bits, but I'm getting confusing results.
I've run
Get-TlsCipherSuite | Format-Table Name, Exchange, Cipher, Hash, ...
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Always leaking ext4 superblock
An encrypted ext4 container will always leak the superblock information.
So encrypting an unencrypted metadata file system like ext4 is inherently vulnerable because it instaleaks?
Shouldn't it then ...
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Soundex and encryption : good friend?
We are considering using the Soundex algorithm to improve our search capabilities in our app.
Our app data are encrypted in the DB. (EAS256)
The Soundex result will be stored in clear next to our ...
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Asymmetric encryption of very small messages
I am working on an application which has a requirement to send very small messages (<64 bits), asynchronously, and using secure asymmetric encryption. We've experimented with simple RSA + OAEP, and ...
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Encryption Algorithm With Separate One-Way (Hashing) And Two-Way (Decryption) Keys
In cryptography, generally we have two ways of handling sensitive information.
We can use one-way encryption such as hashing. This is useful when we never need to retrieve it again. In this case, we ...
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One-way cryptographic algorithm with distinct output and verifiable property
I'm working on a API which is serving content based on user requests. What I'd like to achieve is as follows: Having a constant key stored both on the server and the client machine (as a means of ...
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Security technologies that implements security through "organic-like" obscurity? [closed]
Are there any advanced security technologies, for example, establishing a secured connection, which first require authentication based on security through organic-like changing obscurity of secrecy?
I'...
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Shuffle Tool / Software [closed]
I use GPG symmetric, to encrypt text file.
Is it possible to use GPG symmetric, to encrypt a text file, and at the same time, add additional setting to the encrypted file, to give us 2 conditions:
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How to prevent dos(denial of service) attack? [closed]
Hi is there any solid algorithm or solution where I can refer to for preventing dos (denial of service)attack on my apache server ? I did the dos attack using slowloris in ubuntu and switchblade in ...
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Is MD5 hashing possible by divide and conquer algorithm
I would like to compute the MD5 hash of a file
The file is uploaded to my webserver by my clients
The file is uploaded in pieces (called chunks)
The client also sends the md5 hash of the file so that ...
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Is there any secure method to have recoverable passwords?
I have a local application that normally authenticates against a remote Active Directory server. If the local host loses network connectivity, a special local account becomes available for login. ...
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How should I protect an algorithm that I want to sell?
I created a trading algorithm which I want to sell. People would be able to buy the "bot" at my website and it would run from there on (if this is even safe to do).
What is the best way to ...
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Certificate Signed Using Weak Hashing Algorithm impact on a workstation
I did a vulnerability scan on some of our company workstations. These are workstations used by employees (dev, HR, accounting, etc.) to do their job.
One of the common result I found is SSL/TLS ...
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Is it possible to brute-force the original message of SHA-256 given the size of original string?
Given the SHA-256 hash, the size and the encoding of the original string, is it possible to recover the string via brute force? How many string of a given size will result in the same hash?
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How to interpret security impact of "Server Signature Algorithms" (sslscan)
I'm looking at the results of an sslscan of an internal web application, which reports the following:
I'm not sure how to interpret these and couldn't find an elaboration of what exactly this ...
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Algorithm for quadratic voting in anonymous decentralized systems
The question is about voting in decentralized systems. Quadratic voting is a wonderful way to reach consensus without arranging property qualifications. However, quadratic voting requires a KYC: ...
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Is a random number secure (enough) for card numbers and pins?
I've been given the task of generating some gift tokens which comprise a serial number and a pin number, analagous to a pre-paid credit card. The serial and pin will be printed on a card, with the pin ...
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Thick Client memory encryption
I came across a thick client application recently. The application temporarily stores sensitive data (like username and password) in clear text in memory and the data is flushed once the user logs out ...
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How could I verify that a contract was actually sent to me from the client as soon as the contract is received?
If I want to store electronic contracts for clients over a long period of time. I need to make sure that those files are not readable by anyone other than the client until the client retrieves them at ...
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How to implement challenge-response with keyed hash algorithm when 2 people share same key?
Suppose that 2 people have a keyed hash algorithm (that is, a MAC) with a key that they both know. How could they implement challenge-response using their keyed hash algorithm? This confuses me...
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Is there such a cryptographic algorithm?
Is there such a cryptographic algorithm that will encrypt any file with a password. But when decrypting, if the password is incorrect, the file will be decrypted, but instead of relevant data there ...
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Using a home-brewed hash for passwords for a insignificant website
First off: I do not, nor intend to, use a home brew hash functionality, ever. I'm aware why one shouldn't do that and have read enough topics about it to know it's foolish to do.
I understand that I ...
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Search for existence of sensitive substring without revealing substring in cleartext
I have a list of very sensitive strings and I want to ensure that these strings do not exist in a set of documents (potentially very large documents).
However, these substrings are so sensitive that ...
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What is the difference between EDE and EDE3?
I was going through the OpenSSL cipher algorithms list. I found these two:
des-ede-cbc
des-ede3-ofb
What does that exactly mean? What is the difference between EDE and EDE3? What are the key-size ...
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Most secure algorithms for KDF and Public Key Encryption [duplicate]
I'm developing an application which will need to derive a private/public key pair from a user provided password, and then use the public key to encrypt some text (up to 1000 characters in length) such ...
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Can a hashing function be implemented insecurely?
After working on a an imaginary security related project, it was decided that the project is going to use the imaginary hashing function X.
There are various implementations of the hashing function ...
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IPsec installed algorithms
What happens if a laptop and a server don't have a encryption algorithm in common?
Does IPSec abort the connection or does it always have default algorithms?
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Custom password security algorithm? [duplicate]
How secure would it be if you applied custom algorithms (that you obviously wouldn't reveal to the public) to a hashed password? Like splitting up a hashed string, shuffling it around, possibly even ...
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Can we implement custom algorithms to encode and decode wifi password hashes between Windows 10 and our Router?
Windows 10 has its own way of encrypting hashes, but these can be brute-forced by hashcat. One of our students created 2 of his own password encryption algorithms in python (One for encode, one for ...
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Which algorithm is safest if we exclude AES, Twofish, Serpent and Whirpool?
TLDR: Which algorithm is safest if we exclude AES, Twofish, Serpent and Whirpool?
My threat model is archiving and backing up important and private files.
Files will be stored in many places ...
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Safe encryption algorithm that works with files bigger than 68GB
In my Java application, I used AES/GCM/NoPadding algorithm for encryption, however it throws an exception when I try to encrypt files bigger than ~68GB. From what I read, it is limit of data that can ...
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Differential Privacy: understanding sensitivity [closed]
From this link on Differential Privacy, the L-2 sensitivity is defined as follows:
Question:
Here's my understanding of the above equation:
Make a set of D' data sets such that D' is same as D ...
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Encryption and Hash algorithms explanation
I am using Veracrypt and there are encryption and hash algorithms
Can anyone explain simply what do each algorithm does?
Encryption algorithms encrypt your data/file, Hash algorithm hashes your ...
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If I have the input and output, can I know the encryption technique?
I have a program that can encrypt text, I tried to discover the encryption that is used in this program and could not figure it out, knowing that if the plaintext is P and the encrypted text is C, if ...
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What is the standard practice to maintain a password for different websites? [duplicate]
I have come across many users who maintain a re-used password for each and every website, such as P@ssw0rd123
The problem with this approach is if someone breaches the protections of a particular ...
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Verification After Data Wipe
A lot of data wipe algorithms have the final wiping pass with random characters. They discuss about verification after the wipe. An example of this is from this link:
https://www.datanumen.com/blogs/...
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WPA technical doubts (3)
This is the third post about the set of doubts that came up when I tried to understand WPA3. I am new to this world of cyber-security so every bit of help is welcome!
Someone told me that in WPA2 ...
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Do all Authenticator Apps use the same algorithm?
I've tried some Authenticator Apps (Google,Microsoft,Authy,Lastpass,...) and all of those apps generate same one time passwords at the same time ?
So, these apps are use the same algorithm which is a ...
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What encryption algorithm outputs 22 characters string? [duplicate]
I have a bunch of encoded strings and I am trying to figure the encryption algorithm behind it. I would appreciate if you could help me find which encryption algorithm it is, or if you could point me ...
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What is a trans-cipher?
While discussing archive authenticity/integrity for long term and the problem of potentially re-keying in case of compromise, someone came up with the term "trans-cipher" (or "trans-ciphering").
I ...
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What is the algorithm used by Genie intellicode?
How exactly do Genie Intellicode, and other "Rolling Code" garage door openers achieve their security?
A lengthy Google search didn't turn anything up, which in and of itself gives me cause for ...
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Is this Python program secure?
Note: I'm new to information security practices so feel free to point out anything I could be doing better.
Situation : I'm currently creating an encryption system for instant messaging and I want to ...
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Is there a standard checksum for verifying multipart key fragments?
We will have a symmetric key arriving in three component parts. Once all parts arrive, the key custodians will get together for a ceremony where each enters their part of the key into a secured ...
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Implementation of diceware: do I have to simulate dice roll?
I am creating a small utility for generating passwords based on the diceware method. At the moment I am very close to the algorithm of real diceware - i.e. I simulate rolling dice n-times to get a ...
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Elgamal encryption algorithm
I have question about elgamal algorithm, Why NIST do not certified this algorithm, And every implementation of this algorithm in Python language have Vulnerability?
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Why is asymmetric encryption less efficient than symmetric encryption?
It's common knowledge that asymmetric encryption is in general much more expensive to compute than symmetric encryption, thus common practice is to use asymmetric encryption to establish a symmetric ...
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Is there a difference between encryption keys and encryption certificates?
Learning about cryptography. Experimenting with attacking the algorithm it's self. My question regards vocabulary basically. Are encryption keys and certificates the same thing or are they different?
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Promotional code based on numerical value
I have a field userid which has value between 10000 and 999999. I want to create a promotional code which is based on this field.
The promotional code will be used by the users to refer new users.
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How to responsibly disclose a vulnerability in a widespread algorithm?
Just to be clear, this is purely hypothetical.
Yesterday I got hit in the head with some bricks and, in the haze of concussions, discovered a perfect preimage attack on SHA2. For any given hash, I ...
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Rearranging hash adds no security?
I'm a rookie when it comes to Information Security so I've been reading a lot of the top questions on this stackexchange for the sake of learning. I came across this question that discusses hashing. ...
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