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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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Isn't it almost always not helpful to just change the password of a container after a leak?

Let's assume, an attacker gains access to an encrypted container with a weak password. They start a brute-force attack and I assume they will succeed. To protect any content which has been added to ...
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3answers
10k views

Is EncFS secure for encrypting Dropbox?

I've encrypted my Dropbox folder with EncFS according to a few tutorials I found on the web, advocating this approach. But I've found the following critical statement concerning EncFS's security in ...
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0answers
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Is it still not advisable to use recent versions of EncFS >1.7 to encrypt Dropbox?

I'd like to use EncFS to encrypt files synced with Dropbox. Unfortunately, its Wikipedia page https://en.wikipedia.org/wiki/EncFS mentions security concerns from an audit of version 1.7: EncFS is ...
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2answers
7k views

Do Veracrypt encrypted volumes have any kind of brute force protection?

I have a 10mb encrypted volume which I made with Veracrypt and was planning to upload it to the internet. I have a pretty strong password but was worried about its protection against brute force ...
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4answers
32k views

Why would I ever use AES-256-CBC if AES-256-GCM is more secure?

I guess the gist of my question is: Are there cases in which CBC is better than GCM? The reason I'm asking is that from reading this post by Matthew Green, and this question on cryptography stack ...
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0answers
45 views

How secure is Microsoft's Office and LibreOffice's password protection?

AFAIK both Microsoft Office and LibreOffice have features to add passwords to protect the content. In general, there are two ways: protect from editing/changing (without a revision at least) protect ...
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2answers
146 views

How is it possible that hardware-encrypted flash devices are safe?

I start with the fact that I understand how flash devices (pendrives) can be encrypted with software, for example Bitlocker. Simply, the encryption key is the password given during encryption and ...
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1answer
62 views

How to protect file integrity and history containing counters

I would like to create a solution that would sign the data and will have a increasing counter so I can track the number of signatures. One of the requirement is to have an increasing order of ...
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0answers
44 views

Which attributes does DPAPI's “UseMachineProtection” use to identify a machine?

We're using DPAPIProtectedConfigurationProvider from the Windows Data Protection API to encrypt an application config file. The API offers a property called UseMachineProtection, so that the config ...
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1answer
137 views

Can we write both encrypted text and plain text to the same file?

We have a requirement from customer to write payment transaction information to a text file. Of many lines of data per transaction, only one line contains cardholder information, which needs ...
0
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1answer
157 views

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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2answers
209 views

Is it too late to encrypt my already used USB drive?

I've had my USB for quite a while now. It contains quite a lot of personal information on it. (I know, I'm stupid for not encrypting it before hand). Is it too late to encrypt my drive even if files ...
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1answer
887 views

EncFS vs EFS advantages for Dropbox-seamless encryption

I am considering a solution for securing my private data in Dropbox. In spite of OneDrive, MEGA and AmazonCloud are also being considered but now I put my focus on Dropbox as the most feature-rich of ...
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0answers
61 views

Cracking Zip File Password Encryption [duplicate]

Hey all I am currently taking a computer security course and while doing some research in cryptography I found that it was possible to crack the encryption of a password protected file in an encrypted ...
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1answer
91 views

Is GPG symmetric (decryption) vulnerable?

Suppose a file (say, a text file source.txt) was encrypted into danger.gpg using GPG symmetric encryption on a compromised device. Since the device is compromised, danger.gpg could have been created ...
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0answers
38 views

Why boxcryptor use hybrid cryptosystem to encrypt files

I do not understand why they need asymmetric key encryption, if the client does not use the public key. As far as I understand it, the user password is used to decrypt the private key and no public ...
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3answers
2k views

Linux Plausibly Deniable File System

Is there any way to encrypt a Linux filesystem in such a way to maintain plausible deniability? E.g. "Hidden OS support," the way TrueCrypt and Veracrypt work, they only support Windows OS due to low ...
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0answers
38 views

When using openssl to encrypt a file, how would I create a key made up of specific letters? [closed]

I want to create a 128bit AES key made up of specific letters. I think I would need to use something like openssl genrsa -aes128 -out privkey.pem or openssl genrsa -out privkey.pem but I'm not ...
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1answer
195 views

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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8answers
9k views

Are there any “real world” implementations of secret-sharing encryption schemes?

Imagine something like TrueCrypt where user A can decrypt his files, or any 3 of the 10 directors in his organization can decrypt user A's files. As I understand it this is similar to the way the ...
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2answers
59 views

What program can Decrypt specific a Folder/Files during Windows Boot/Loading? (Windows)

I've been looking into Encryption of my data for some time now; I've decided to move ahead with VeraCrypt for encryption all of my partitions (I have 2 disks in 1 laptop) except for the OS (C:) ...
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2answers
83 views

File integrity assurance

I have the following scenario : Two parties want to exchange files. First party publishes a file on a secure server First party sends to the second, a hash of the file in order to be able to verify ...
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1answer
103 views

Will prepending random data (of random length) result in more secure communication?

Many files begin with a "well-known" header sequence which I imagine helps a lot in performing cryptanalysis over a huge number of data transfers. So I have the thought of prepending a block or two ...
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1answer
66 views

How file-level security works?

How a file-level security system works internally? For example https://en.fasoo.com claims that if someone in your organization trys to leak information you will be noticed ( They didn't say this ...
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1answer
38 views

Storing files in database through encryption and Viewing them only on providing key for the file

I have this use case: User1 uploads his file into the database which should be encrypted. Any other users who request that file, user1 will be notified for approval, on approving other users should ...
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2answers
5k views

How secure is the 2016 XLSX Excel Encrypt with password function?

Is this able to be cracked without a brute force? With a long enough password, would I be safe storing my nuclear launch codes in an encrypted excel sheet?
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2answers
61 views

Detecting Spoofed InDesign File Creation Date

I apologize for turning here with a question, my research both searching here and on Google has only turned up useless information. I believe that someone has sent me files that have had their file ...
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1answer
31 views

Best practice for config files for ec2 instances

I am building a lamp server ec2 image for a project we are doing. These images will be in an autoscaling group and on startup will be running startup script. THere are some config files that have ...
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1answer
50 views

Is there any 'Open Enrypted File Container' Format?

Tools that create 'encrypted file containers' use open encryption standards like AES to encrypt container contents, however the container format is proprietary, I am guessing, so need the same tool to ...
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2answers
154 views

Can I use RSA to encrypt an AES256 key that I put at the beginning of my AES256 encrypted file?

I have a master server generating large files for other (known) servers to download. Those files: Are quite big. From 20MB to 5GB. Are written once by the server and then it forgets about them. ...
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1answer
218 views

Encryption for cloud storage

Background / Requirements using a Windows machine hard drives are already (veracrypt) encrypted volumes not relying on any cloud service provider to trust them with their encryption file by file ...
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1answer
70 views

Backing up an encypted drive on an encrypted drive

I have searched, and have been unable to find an adequate answer to my question. My apologies as I'm sure this is a relatively elementary question for the users here. I have encrypted my Windows 10 ...
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1answer
256 views

How secure is a 100-bit password in 2018 and onwards?

Long story short, I share a server with a few other people and store my backups there. All these backups are archived to a .7z file using AES-256 encryption, using a randomly-generated password of ...
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5answers
20k views

What does Windows's built-in encryption do, if I can seemingly always read my encrypted files?

I'm playing around with certificates and encryption on a Windows system, but either it isn't working or I don't know how it should works. When I encrypt a file its name changes to green. But then, I ...
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2answers
448 views

Why providing many protected zip files will increase the chance of retrieving the password

In fcrackzip man they say : the more files you provide, the better. I want to know why. What's the method it uses to retrieve the password?
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1answer
40 views

Potential security issue with md5 filename

I've been storing files using a filename of the md5 hash of the file. This allows me to not store duplicates of the same file and avoids any filename clashes. Each file has uses a different salt/iv. ...
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2answers
2k views

Which is more secure a full disk or file encryption? [duplicate]

There are probably two ways to encrypt your computer full disk encryption which completely locks down the computer between when it is off and when it has booted but after everything loads you computer ...
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1answer
190 views

Crypto-shredding & backups of keys

I was wondering, how is crypto-shredding implemented in an environment, where data backups/mirroring is mandatory for the "key database" - as it must not be possible to lose the machine/db with all ...
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5answers
13k views

How secure are the password files used by Password Safe and Password Gorilla?

Password Safe and Password Gorilla are both programs to manage passwords. Both store a list of user passwords in a file, which is encrypted using a master password. They use the same file format, so ...
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1answer
83 views

Recognise tool by which file was encrypted [duplicate]

I have file with extension *.encrypted. Can you give me some advice how to recognise by witch tool was this file encrypted? It´s not encrypted by some ransomware but by some encrypt tool. When I open ...
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1answer
171 views

Dropbox ransomware experience

How Dropbox handles ransomware issues? Can it effectively restore files encrypted by ransomware? The reason I am asking is because I am looking for a bullet-proof solution against ransomware and ...
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1answer
1k views

openssl vs gpg for file based encryption? Pros vs cons for security?

I want to encrypt a tar archive and optionally a block file system (akin to DMG image). Does anyone know the pros vs cons of encrypting each with OpenSSL vs GPG? I ask because some have stated that ...
15
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8answers
13k views

Keep encrypted files in sync on a cloud service, without having to upload an entire encrypted volume each time

Situation: User has several folders worth of GBs which they want to keep in sync on a cloud service (for example Mega or Dropbox) in an encrypted form; User does not want to sync a single encrypted ...
4
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2answers
141 views

Is it safe to upload a read-only encrypted volume to a cloud folder?

I know keeping an active encrypted volume (like a VeraCrypt drive or a simple zip folder encrypted with AES256) on Dropbox/OneDrive/Gdrive/etc. is risky; data can be corrupted and the pattern of ...
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2answers
16k views

Excel 2007 Encryption Strength

With a strong password of 10+ characters, mixed case, etc... is the encryption of an Excel 2007 document secure enough to create reasonably strong defense against a brute force attack? What ...
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0answers
25 views

Using the same passphrase for files and filenames with filesystem-level encryption such as eCryptfs

In filesystem-level encryption schemes where files are encrypted and stored individually, filenames may or may not be encrypted. eCryptfs allows to encrypt filenames with a different key than the one ...
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1answer
942 views

Is it safe to keep my KeePassX database on my server or cloud with encryption? [duplicate]

My KeePassX file has a long and strong password. I've read several articles and discussions about how safe it'll be stored such a file on VPS or cloud service such as Dropbox. There was no consensus ...
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0answers
82 views

Can Gmail read password protected .docx files?

Can Gmail read MS-Word .docx 2011 (OS X) files that require a password to open? As I understand it, Gmail servers read emails and attachments in their efforts to characterize users for advertising ...
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3answers
3k views

Encrypted password inside compressed archive

File compression utilities like Winrar or ZIP or 7zip encrypt the password and store it inside the archive. How safe is that? I mean you are giving away the archive with the password inside,it's not ...
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1answer
214 views

Is there any mechanism that using multiple keys encrypt and decrypt a shared document?

I wanted to achieve the following mechanism to encrypt a document each person in a group of N (user a, b, c...)has her own key; user a and user b somehow decided to encrypt document M, and they can ...