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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Securing integrity of a large file with cryptography

Let say I have a large file that is of considerable interest to the public and I want to publish it. The plan is to hash it using reliable function and publish its hash on a public blockchain (btc or ...
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Using unencrypted parts of encrypted file to recover password (7zip)

I have forgotten the password for an encrypted 7zip file (the filenames are not hidden), and I have copies of some of the unencrypted files. Is there a way I can use this to find out what the password ...
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Rar password when you have unencrypted and encrypted file

I have two files (file1 and file2) where file1 is encrypted with rar software and file2 is the original plain text. Does anyone know the fastest way to get the password used to rar the file?
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Disk Encryption vs File Encryption for Embedded Linux?

The Security page for Android discusses file-based vs full-disk encryption. It discusses some rationale about why FBE in Android 7.0 is an enhancement over FDE when it come to a smartphone. But, if ...
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How can I share files with other individuals using the cloud in a secure way?

I would like to use a dropbox because it is easy and convenient. But I want to encrypt the files with the public key of the intended recipient, so he will be the only one who can access the data in ...
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Best way to reduce encryption of the big files

I want to share a big file(All existing formats) with others. As I'm using Android phones as client/server I want to reduces the CPU overhead and Time it takes to encrypt/decrypt. My idea is to use a ...
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1answer
543 views

Is there a ransomware variant that checks for file's magic numbers to encrypt?

Is there a known ransomware-variant (Cryptolocker, Cryptowall etc.) that before encrypting the files checks for their magic numbers? Lets say that there's a Word file, that had its file extension ...
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How can I select a compression utility that is popular and secure enough

In a previous posting on Which is a safe way to transfer a copy of a sensitive document?, I have received suggestions to compress and encrypt an attachment file using the options of utilities such as ...
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Way to secure store personal data

This is not for business or corporations, but for personal situations. I rely on gsuite, google drive, google docs, etc.. not that too much 'heavily', but I use it to send most of my business emails, ...
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778 views

Securely storing AES key with public key cryptography

Security newbie here I have a bash script that recursively enumerates all files and directories from a given path (say /home/user) and encrypts individual files and stores them into another directory ...
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Will editing a Word file from a mounted Truecrypt volume leave any trace behind on the host computer?

I've heard that even if you have a Word document encrpyted (just using the built in Word encryption tools) and are editing it, it can still leave behind remnants of a file on the local computer in ...
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Is volume level encryption enough to satisfy compliance requirements?

We are implement a cloud application and using nosql technology. We know there are quite a few compliance requirements out there require doing data encryption at rest. However, we would like to know ...
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Data encryption risk with bad sectors?

A few decades ago, I've known hard disks and floppy disks which developed bad sectors or crashed. So now when I want to use an external hard disk for backups for a startup company, the first thing ...
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Does Wanna Cry encrypt files on network drives?

I've dealt with ransomware threats in the past, such as LOCKY that not only encrypt data it considers user documents found on the local machine, but also on any network drive to which the user has ...
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(Why) does an encrypted MS Office 2010 Spreadsheet (need to) have the password hash “written down”?

To my naive mind, it seems like the encryption of a document with AES should go like this: HumanPassword ---|hash|--> key ---|AES|--> Ciphertext plaintext|--^ And the ...
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Encrypted file system in a hosted linux system

I'm considering to use an encrypted file system (dm-crypt or gocryptfs) in a linux system hosted by Linode. Can the administrators of Linode access the mounted (i.e., decrypted) contents? I'm not sure ...
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Is it possible to recreate a file using only its hash [duplicate]

To my knowledge, a file can have only one hash and a hash corresponds to only that file(keeping aside the 2 file one hash bug). Using that knowledge is it possible to make an algorithm to recreate a ...
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Hardening password-based file encryption with a synchronous stream cipher plus high-memory hashing algorithm?

So this is probably a stupid question, but I'm trying to understand why the following isn't done for at-rest files encrypted via password: generate an AES-256 key/salt/iv take the plaintext message (...
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269 views

which places are used to store the the encryption key? [duplicate]

So i have an encryption key which i will use to encrypt data or sign data with it. But in order make it possible to ensure the data integrity, i have to keep the key secret. So i thought of spliting ...
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Windows EFS Files Spontaneously Unavailable

We are trying to secure a folder with over 1 million very small text files using Windows EFS on Windows Server 2008 R2. We already have an infrastructure in place for backing up keys and data. We ...
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Is encrypting home sufficient?

I currently have a fully encrypted Windows System, and I'm looking at switching to Ubuntu. Is encrypting my home directory (with ecryptfs) sufficient? On windows this would be problematic due to ...
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Is there a good way to use to find out how this was encrypted [duplicate]

Ok, so this is a very basic cryptography question. I have captured a message from an Android app to a server. I believe this app may be stealing information from the phone it is on so I'm running it ...
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Encrypted NAS where only clients know the (decryption) key

Is there an implementation of a file-sharing network protocol where the server has no idea what data is being stored, but can serve the encrypted files to clients that will decrypt them on-the-fly (if ...
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Do spaces in a passphrase really add any more security/entropy?

I often see passphrase suggestions written as a sentence, with spaces. In that format are they more susceptible to a dictionary attack because each word is on it's own as opposed to a large unbroken ...
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Downloading a file from a server with a secret: in text or binary?

Suppose, a user can click a button on a website and downloads a file with a secret. Via ajax. Is it more secure if a server generates that file and sends it as 1) zip, tar or the like -- a binary ...
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How to create a format that is very difficult to reverse engineer? [closed]

I am learning about file formats. I have an application that will do analytics and will have some personal information. I need to make it such that only some people are able to access data and even ...
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1answer
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Secure file storage in cloud as backup

At start I'll admit I'm a total newbie when it goes for stuff I want to achieve, but I'm willing to learn, so sorry in advance for writing total nonsense. Stuff I want to achieve: I want to store my ...
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Encrypted file to Remote Storage

Suppose I wanted to send some files to a remote storage device and (reasonably) guarantee their security and I am wondering whether something like the following method would be suitable: Encrypt a ...
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1answer
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Best way to secure a cross-platform mobile app for HIPAA compliance

I'm developing a cross-platform, offline first mHealth application using Ionic 3 and Cordova which may need to be HIPAA compliant in the near future. It uses PouchDB as a client-side DB, HTTPS, at-...
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File encryption at rest, password considerations

I have at most 10,000 files that I want to store encrypted with one password. The current idea is: Have 1 master file containing (expensive) parameters for scrypt. For encryption/decryption hash a ...
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Encrypting File System Data at Rest on Windows Web Application

We have a web application (running in Apache Tomcat on a Windows Server 2008 machine) that stores most of its data in the file system. We are investigating ways to implement encryption for this data ...
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2answers
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What is the point of encrypting my files (on a server); if I can decrypt them why can't a hacker do that too?

I help maintain a webserver that users use. They store data on our server. Most of the data is not sensitive, but some of it is highly sensitive. So, it seems like we want to encrypt it so that if ...
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User login credentials used for file encryption

A system I'm implementing requires a user to create a single user, with a single login password. I want to have a single password for the system, and not require multiple different password entries ...
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VeraCrypt/TruCrypt - I can't understand why you'd want to create a “hidden” volume…?

I can't think of a reason as to why you'd want to create a hidden volume in VeraCrypt. It says because "you may be asked to hand the information," but why would I need to hand it over? Nobody has any ...
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Secure upload/download design with malicious storage server

Assume we have a malicious storage server (a user-agnostic key-value store, supporting server.put(key, value) and server.get(key)) that we want to use for per-user based secure file storage. The two ...
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How is encryption different for Windows yet they are identical?

I right clicked on C:\Users\USERNAME and did advanced -> enable encryption. On one laptop it turned green. The other it shows an icon on the files with a lock. What is the difference between these? ...
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How can I allow access to encrypted data if only 2 out of 3 users provide a secret?

I want to encrypt data, but make sure that no single user can decrypt the data. Further, it is important not to require ALL users to be present to decrypt. This will allow for some flexibility and ...
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Could ransomware be stalled while encrypting?

I have been reading about ransomware, and I was wondering if it could be defended against by having certain "trap" files on a drive. Sometimes I look through Code Golf and am thoroughly impressed by ...
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What is the impact of RSA key's size on CPU load?

I use ssh connection encrypted and compressed. If I use small RSA keys or very big RSA keys, what is impact on CPU load for compression, for decompression and on bandwidth (encrypted file size) ?
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How to encrypt a file with code? [closed]

How can I encrypt a file using my own programming code? I am a beginner, I want to learn encryption.
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What's the point of encrypting a session key with a master for file backups?

I was reading the Arq backup data format specification. In short (if I've understood right) it is: Generate password protected master key Generate random session key Encrypt plain text with session ...
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Ccrypt versus 7zip encryption

I'm on Debian and I have a folder, with thousands of files inside it, that has a size of about 14GB. From this folder I have created two encrypted archives: one is a password protected .7z archive, ...
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Is it safe to encrypt multiple files with the same strong passphrase?

I use GPG to symmetrically encrypt multiple files, and it would be more convenient if they all had the same strong passphrase. It's possible that someone could gain access to several of these files. ...
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Securing connection credentials on a web server

I'm in process of creating a tiny blog platform and I've encountered a pretty controversial topic of storing connection string to a DB securely on a host. Here is a reference question: How to encrypt ...
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1answer
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How can I compare GPG encrypted files in order to upload only the ones that have changed? [duplicate]

This question follows this one, in regards to encrypting files individually in order to upload them to a cloud service. --- Scenario: I have my folder full of unencrypted files Via script I make a ...
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1answer
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Will new data written to disk while BitLocker is encrypting the disk be encrypted?

When you enable BitLocker, there is a period of time where BitLocker is slowly encrypting the contents of the drive in the background. During this time, is it guaranteed that new data written to the ...
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Secure backup encryption with OpenSSL

I know, the general advice is "keep your hands off crypto stuff". And the standard way to encrypt backup data securely would be using GnuPG. However, for a rather academic exercise, I would like to ...
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Technology that can survive a “Rubber-Hose attack”

In the documentary film Citizenfour, Edward Snowden says about documents: I'm comfortable in my technical ability to protect [documents]. I mean you could literally shoot me or torture me and I ...
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Brute force algorithm to break symmetric key. How to find the program when current key is the correct one?

In a brute force program, sequential keys are tested against the public key in order to find the correspondent private key. My question is, how is the test done with each key that let you conclude ...
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Is the MSWord password protection vulnerable?

When encrypting MSWord documents within the Word 2016 app (most recent file format .docx) what encryption algorithm is used? Have any vulnerabilities been found thus far? Has it been audited? Edit: ...