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Questions tagged [file-encryption]

The process of encrypting individual files on a storage medium and permitting access to the encrypted data only after proper authentication is provided.

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Loss of data due to encryption

Could any kind of encryption method (AES, etc.) lead to data loss like in lossy compression? I'm interested if data (lossy compressed, lossless compressed, uncompressed) that is encrypted and ...
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Encryption of exe file

I recently started learning cryptography. I have learned some basic stuff. I'm also started learning about pc security, so I was wondering how do hackers use cryptography for bypassing antivirus ...
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How do I safely encrypt a file for transport and storage?

So I need to encrypt a file server-side for transport from server to client and storage on client-side. I'm quite confused as to what I have to watch out for, as it seems like it's insanely easy to ...
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Question about decryption

I have a question about decryption. Let's say I have a bunch of files that are encrypted. Someone gains access to those files, and finds out that he already has one of them, unencrypted. My question ...
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Encrypt a file for random access but only after an initial read of the whole file

I'm symmetrically encrypting a file (using a random salt and a user supplied password with PKCS5S2, i.e., nothing special) and I need to be able to access it randomly. Therefore I'm using a stream ...
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Testing if a password for an eCryptfs mount is valid [closed]

I'm using "eCryptfs" on several directories on my dedicated Debian server. I mount them manually via mount -t ecryptfs [dir] [mountpoint] But after some weeks ...
Jan van Esdonk's user avatar
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What's the preferable encryption for large data and files in terms of speed and security other than AES?

First of all, I'm relatively new to encryption so please bear with me. I'm looking for a way to encrypt large amounts of data only on my device, no need to transfer my encrypted files/data (10-20GB or ...
Ilkay Solotov's user avatar
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How can we encrypt a file to be just readable (and not writable) after decryption?

Is it possible to encrypt a file (e.g., a text document) such that when a user decrypts it, he/she be able to just read the file and not be able to change the content of the file? I mean, the result ...
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Dangers of using CTR mode for encryption

I know that it is never suggested to use the same key or key/IV pair twice for a stream cipher or for a block cipher operating in CTR mode. Filesystem-level encryption reuses the same key for a file ...
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What do I use as the encryption key and initialization vector in AES cfb128

I'm writing a program that can encrypt a file using AES cfb128 (using Openssl and C++). The scenario of the program is this: Person A visits computer, encrypts a file they make, takes away a key (on ...
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Learning to encrypt/encryption algorithms [closed]

I am a beginning programmer interested in coding an application of my own to encrypt sensitive files of mine. For example: lists of passwords, bank accounts, Credit Card numbers etc. I was wondering ...
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multi-user deterministic symmetric encryption

I was wondering whether there exists a symmetric encryption scheme such that there is 1 sender and n receivers. Each receiver has 1 random and independent symmetric key. The sender knows the ...
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Faster alternatives to RSA trapdoor permutation

We're working on web3.0 decentralized internet, a big part of which is a decentralized file storage system where clients upload files to storage providers and pay them for the services. Storage ...
Serge Uvarov's user avatar
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Can a hash of the original plain text file be used to brute force an encrypted copy?

I have encrypted files stored on a public cloud, in the same directory on the cloud I have the sha256 hash of the files before they were encrypted in a text file. The keys used to encrypt the files ...
Wilyarti Howard's user avatar
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Encryption algorithms larger than 256 Bit for “big data” encryption?

I'm somewhat new to encryption. When looking at encryption programs for big data, I frequently see a maximum of 256 bits. Why do we generally restrict our (symmetric) keys to 256 bits? Can more ...
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Given an encrypted file, what are possible ways to find its encryption algorithm?

Given an encrypted file, what are possible ways to find its encryption algorithm? Heuristic ways are okay as well.
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"Appendable" encryption scheme

Are there any encryption schemes that could be classified as "appendable"? By appendable I mean being able to add new data to the end of already encrypted data, without needing to decrypt ...
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Deterministic salt for KDF

What would be recommended way to make deterministic password based file encryption? I can use SIV mode, but KDF (like Argon) takes salt for which I could use SIV tag, but I cannot make it because I ...
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How to hide multiple types of information in the same file?

I have a vague memory of watching a video of a guy "unraveling the secret story / lore" from the game Doki Doki Literature Club. And I remember that he took a file, converted it to .txt and ...
MessiasOF's user avatar
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Low Encrypted Entropy on PDF File

Thank you for the answers, I have edited my questions. It is a known fact that encrypting the files increases the file entropy. You can see the average entropy values of encrypted and non-encrypted ...
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Does encrypting different versions of the same file or folder with the same key make it easier for hackers to attempt the decoding?

Assuming the hacker has access to the ciphers of each of the versions, will it help him/her to decipher the original file(s) by doing some sort of comparison of the ciphers?
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Which symmetric algorithm should I use for storing files in untrusted servers?

I have gigabites of files, which I have to backup. I have some servers for storing this files. But these servers are untrusted. So I need to encrypt files, then backup files. When my PC breaks down, ...
Max's user avatar
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Robust cryptosystem for files/chunks protection?

I'm not a cryptographic expert by far but I do understand that when it comes to cryptography it's best to stick with established standards. I have to ensure confidentiality and integrity of a bunch ...
sgable's user avatar
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Why does Apple use One-Pass Diffie-Hellman for file encryption?

I was reading the iOS Security Guide (snapshot) and stumbled upon the following file protection class on page 15: (NSFileProtectionCompleteUnlessOpen): Some files may need to be written while the ...
edigaryev's user avatar
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Crypto lib that use files instead of passphrase [closed]

I would like to program an application to allow people to encrypt files without using a password or pass-phrase but an arbitrary long file. I'm searching for a library that allows me to safely create ...
metas's user avatar
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Using what we already know about the data to decrypt it?

Are there any methods or tools out there that let us use what we know about the data in order to crack the encryption? For example let's say I get access to an encrypted database file but I know ...
ThomasRones's user avatar
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Does my asymmetric/symmetric mixed file encryption pseudo code pass sanity check?

I realize this depends on my implementation and the implementation of the libraries I use. I am asking about my process assuming that the encryption libraries and my code are not flawed/compromised, ...
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How to crack rar file with protected pass with only the AES-256 key [closed]

I have rar with protected pass.But I have the AES-256 key can I crack it and if I can. how?
עידן כהן's user avatar
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Safest method for encrypting a file on a local machine

I am looking for a safe method to encrypt a local file on my machine. Let's say I have a file containing my logins and passwords -- how can I make sure that the encryption is reasonably sufficient in ...
Proto Ukr's user avatar
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Can multi-encrypted file be decrypted with one password only?

Let's say I have a single file I want to encrypt with AES and I encrypt it twice (first encrypt the unencrypted file, then encrypt the encrypted file again). The first time I use password 'ABC', the ...
yeti's user avatar
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Warding an ECIES setup against MitM: ECDSA?

Is it necessary/appropriate to digitally sign an ETM file in an ECIES context? The encryption mode is CTR(using Inferno). The current output is: [shared public key] [ciphertext] [MAC]. The encrypted ...
Frank's user avatar
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research on Encryption for master [closed]

I'm tring to choose an way for an Encryption mothod for my research? So,I want to choose one-layer encryption or multilayer encryption,and I want it to be easy to applicable. when I search about it, ...
Hussein's user avatar
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FileVault AES-XTS decryption with cipher text that's missing a part

My mac was recently upgraded to OS X Yosemite and FileVault2 full disk encryption was turned on. Encryption finished, but things went horribly wrong and key parts of the disk are filled with all 0s (...
Mike Haboustak's user avatar
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636 views

RSA or Paillier is good? [closed]

I want to implement file storage in cloud using homomorphic encryption. I want to use paillier encryption. Can you suggest the drawback of RSA to store and retrieving the files. Then only i can use ...
rukshana's user avatar
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How to handle authenticated encryption for big files?

First I need to mention that I can't use BouncyCastle to implement this solution. I have to encrypt files into the file system. Those files are not going to be tranfered over the wire to any other ...
alejo's user avatar
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Using RSA key pair for file encryption [closed]

I'm looking for a way to perform encrypted nightly backups of a server I administer, without storing the decryption key on the server. A form of PK encryption seems ideal for this, as I can store the ...
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File Size Shrinks After Encryption

I am a Bitcoin enthusiast, but I have never been formally trained in the study of computer science and cryptography. Recently, I tried a new way to encrypt my private key: I wrote it down on a paper, ...
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How secure is the Vigenère cipher in file encryption if you encrypt the password first?

I created a basic file encryption method, that seems pretty secure to me (based on an answer below, it seems to be an implementation of the Vigenère cipher) , but one of my colleagues claims that it ...
Ephraim's user avatar
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Why does symmetric encryption not provide authentication and integrity? Is it only this type of encryption or cryptology in general have this issue?

Studying for Cryptology and came across a presentation regarding on "Integrity vs Authenticity" where the discussion briefly mentions how Encryption "does not provide integrity or ...
omar7439's user avatar
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Password in first line of file for AES-256 encryption

I'm using openssl with aes-256-cbc encryption to encrypt a file. The password is on the first line of the file and the ...
rrrkren's user avatar
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Hash Comparison to Detect Ransomware File Encryption

As detailed in a separate question, I thought I had a way to detect the type of ransomware that encrypts files silently, and then decrypts them on the fly, so as to prevent the user from realizing ...
Ray Woodcock's user avatar
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3 answers
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how much is secure to encrypt a password using itself (as encryption key) for storing it on an insecure media?

I want to store a password securely on a storage (suppose in a usual unencrypted file). I use this password as AES key to encrypt itself (using AES-ECB) & then store it on the media (the password ...
Ehsan Khodarahmi's user avatar
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Does using ECB mode of Vigenère cipher on files (no plain text) with a key of 10,000 byte(char) is secure in today's standard?

Hi I'm fairly new to studying cryptography and I'm just curious about the security of Vigenère cipher. Given today's powerful super computers, how secure/unsecure does Vigenère cipher can get? let us ...
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How to be able to change the password to access data encrypted with AES-GCM, without reencrypting?

Let's say you need to encrypt plaintext which is 1 TB big. You have a password pwd. This very classical AES-GCM process is ...
Basj's user avatar
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GnuPG - provide encryption key for AES rather than deriving it from passphrase

I'd like to encrypt a file with AES256 and provide my own 32-bytes for the encryption, rather than having GPG derive it from the passphrase. I could not find such option, but I'm thinking about a ...
Slimevine's user avatar
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Is CBC mode of encryption still safe as long as it's not use to send messages over a network?

I'm still reading about the Padding Oracle attack and Side Channel attack that can be performed to decrypt cipher text encrypted with CBC though it's still not clear to me. But base on my little ...
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Reducing a 64 digit integer to 10 digit

Situation:- I am using Python. I am using RSA and I am using two 64 bit keys. I am not an cryptographer . I can provide you the RSA code if needed but i am not posting it as it doesn't have to do ...
Ritvik's user avatar
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What is the fuss about 'dot blockchain' and music metadata? [closed]

and how does it work? http://wmot.org/post/music-money-and-metadata-promise-blockchain#stream/0 claims that this is an answer to the metadata woes of the music/recorded media industry. I don't see ...
Sherwood Botsford's user avatar
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How to effectively apply combination of Block and Stream Cipher?

I have used TrueCrypt but it uses a cascaded encryption. I want to know about encrypting a file using two ciphers with each cipher having different key. Cipher A (Block Cipher) - with Key KA Cipher ...
RPK's user avatar
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Making a secure file sharing scheme usable

I am trying to realize a secure file sharing scheme based on asymmetric crypto. Users will access this via browser. In short, it works like this: Users register and set their username and password. ...
Theodor Straube's user avatar