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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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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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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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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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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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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
177 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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Is there any sense in encrypting a file for one's own later use?

Let's say you have a single sensitive document. You're traveling to somewhere high risk and are advised not to bring your data, but you also don't have safe storage at home. So you encrypt your ...
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2answers
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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
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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
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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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2answers
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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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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
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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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1answer
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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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2answers
131 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
151 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
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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
235 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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1answer
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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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1answer
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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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1answer
151 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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1answer
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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
154 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
758 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 ...
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2answers
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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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0answers
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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
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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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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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1answer
171 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 ...
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1answer
67 views

Securing a file from getting stolen in an Android application?

I have a secret file which I cannot encrypt (because I am using it in a third party library) in an Android app which I want to protect from reverse engineering. The app will go public on Google Play ...
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1answer
65 views

What are `dd` input blocks? [closed]

I'm looking for a semi-technical explanation of "input blocks". When creating encrypted containers we use dd with "count=n", but I'm not sure of the difference between "count=0" and "count=1". The dd ...
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2answers
245 views

Win10: Access other logged on users' memory

How easily can admin users access the data of other users' running processes on Windows 10? Especially webpages loaded by Chrome. Example Context Bob and Alice share a single Windows 10 ...
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2answers
286 views

Should a password based AES CBC encrypted string have extra security?

For a Java application that I wrote, I take a password provided by a user and generate a 128-bit AES key from it using 100,000 iterations of PBKDF2-HMAC-SHA512 with a randomly generated 512-bit salt. ...
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1answer
446 views

Outsmart Google Drive censorship with 7zip encryption

I use sometimes Google Drive for sharing large files. Google Drive is fast and user friendly. I don't wish that Google sees the content of my files and try to encrypt the filename and content. My ...
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After converting a .zip file to an .exe, can we get the password using a hex editor? [duplicate]

I have a zip file and was wondering if the password can be extracted. Like if I convert it to a exe file and use a hex editor to extract the password. How practical is this method? and also what is ...
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2answers
153 views

Encryption before backing up to the Cloud

I have collected a lot of data (approx 3TB) in photos and videos over the years, I've been upgrading to newer and bigger hard disks and luckily they've not failed on me. I've realized that my access ...
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1answer
94 views

lost key-files for encrypted files [closed]

I had encrypted a file on my computer but the computer got infected by a virus, so I reinstalled Windows on my computer. All my key-files have gone. Is there a way to recreate the lost key-files, as ...
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1answer
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Is an HMAC hash of plaintext data secure enough to use as a lookup index for encrypted data

I'm working on an app that will download files from external servers over https and store them on disk in a relatively secure way. Specifically, using a cryptographically unique IV, an AES256 cipher ...
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1answer
66 views

What client side encryption algorithm/libraries should I use to make syncing easier?

I want to build a webapp and a sister mobile app (using react native) that uses client side encryption. The encryption would be for text entries written on a daily basis that the user could create and ...
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Decrypt to memory for editing

I am looking for a secure way to edit sensitive text data, using Git and Vim in the process. An ideal solution would be: clone the encrypted git repository into memory; decrypt into memory; do the ...
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2answers
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encryption - how to secure files - decrypting exposes them on ssd

Let's say I have an encrypted file. Now I decrypt it but since my computer only has ssd, i decrypt it on the ssd drive. Say, I make changes or I finish using the decrypted file so I encrypt it again. ...
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4answers
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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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1answer
151 views

Should I store my encrypted password's salt and initialization vector as clear text?

I'm encrypting some file with AES-256-CBC, and I'm planning to store the cipher text in a json file, with something like: { "data": "0123456789ABCDEF...", "salt": "00123ABCAABBCCDD...", "...
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1answer
87 views

What kind of encryption is this file using? It used to be plain text

I was collecting data and building a database from a mobile game on Android. Here's an after/before image. If I do CTRL + A and copy paste on the left side, all information gets copied to clipboard ...
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1answer
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The data(username,passwords) stored in app bundle is safe in a jailbroken ios device

I was testing an iphone application in a jail broken device. I happend to see an intresting thing that the username and passwords are stored in a plist file and Cache.db file in preferences directory ...
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1answer
498 views

Encrypt entire CSV file, but decrypt only specific fields?

I have some data in CSV file, say data.csv with columns age, sex, country and status. Is it possible I could encrypt the entire CSV file some way which allows me to fetch only selected columns, say ...
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Program or method to create an encrypted bulk file container [closed]

I have several hundred gigs of data that I store on a NAS for my own usage. The NAS storage solution manages local encryption, however I am looking into cloud backup solutions for disaster recovery. ...
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3answers
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Susceptibility of 7z encrypted archive files to man in the middle attacks

Given: A file (assume 1 GB in size) is encrypted along with filenames using 7zip into a 7z archive using AES-256 The file is uploaded to a cloud storage service such as those offered by Google, ...
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2answers
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What is the best practice for encrypting and storing temp data on client?

I have a client-server system, where the client is an Android app. The client and the server communicate over HTTP. If the server/network is not available, then the client has to store the data ...
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1answer
374 views

What is Cryptographic metadata

I'm learning about how to encrypt a file in a computer system. I'm reading this: https://wiki.archlinux.org/index.php/disk_encryption Here I found an notation: Cryptographic metadata. As I know, ...