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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3
votes
1answer
45 views

Decrypting arbitrary offset of encrypted file

I want to store encrypted files on some storage backend that allows me to fetch bytes X through Y of the encrypted file. I can obviously decrypt the entire file locally and send it back to the client. ...
9
votes
4answers
4k views

Is Changing a File Type and Name an Effective Security Solution?

Is renaming folders & files and changing file types an effective solution for file security of a PC? I am an application programmer and have an extensive background in it. I have written a ...
3
votes
2answers
236 views

Security review: is this PHP mcrypt wrapper class safe?

I was looking for an easy to use library for encrypting files in PHP. PHP provides encryption functionality through the mcrypt library. Yet, there is a lot of configuration options and choices, enough ...
-1
votes
2answers
73 views

Encrypt files on FTP server

I have a practical situation here, my company is a FTP server provider for some clients. The clients are sharing their files on our FTP server and have had no problem with access management and ...
5
votes
1answer
95 views

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) ?
2
votes
2answers
175 views

Security of Microsoft OneDrive

A friend asked about putting some of his data on Microsoft's OneDrive. I did some research, and what I learned seems very surprising. It appears that all the user data on MS OneDrive is store ...
1
vote
0answers
22 views

Clear EFS Cache at Set Interval

My boss wants to set up encrypted file shares using EFS on Windows Server 2012 R2 Boxes accessed by Windows 8.1 clients. I've been able to set the default DRA, issue certificates in test cases and so ...
2
votes
1answer
51 views

ecryptfs - relationship between passphrase and sig-cache.txt

I have previously used TrueCrypt for creating encrypted directories on servers. I am now trying ecryptfs due to the end of development announcement in May. I see that when I encrypt a directory and ...
2
votes
2answers
110 views

Steps for building a good File Encryption on Android

I want to be able to build a good file encryption on android for a cloud app. The files used are mainly pdfs, pngs, docs, audio, video, etc (all sorts of files). Edit: My constrains are that it ...
1
vote
1answer
37 views

Javascript file detection

One common technique I use is xor bruteforcing on binary data. In this case, I would like a heuristic approach to determine whether or not any possible candidate plaintexts are javascript. This rules ...
0
votes
1answer
45 views

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 ...
-1
votes
1answer
46 views

Permutation based file secure

I have a thought. 1. Take a file. 2. Read number of bytes. If its less than 2048, padd it till 2048 3. Read each byte. And create a single file which contains the particular byte. Give a random name ...
1
vote
1answer
35 views

Is eCryptfs vulverable when storing known file trees?

I use the standard Ubuntu eCryptfs setup to encrypt my home folder. As far as I can tell it encrypts the files and their names, but the directory hierarchy is essentially the same. Every git ...
1
vote
0answers
60 views

Is it possible to encrypt Word Docs with something other than default?

AES 128-bit advanced encryption is fairly simple to break and was wondering if there was any way to use a more secure one? And if so - any suggestions?
2
votes
1answer
89 views

NaCL: Encrypt file to multiple recipients

I am trying to understand the Networking And Cryptography Library (NaCL). Consider i have a file that i want to send to multiple recipients. PGP or S/MIME supports multiple recipients by encrypting ...
1
vote
1answer
21 views

Can I keep large encrypted files in my mailbox on mail provider server?

Is there any restriction or policy of large e-mail providers (such as GMail, Yahoo, Hotmail and similar) for keeping/storing large encrypted files by the users within their disk quota in 3rd party ...
1
vote
1answer
195 views

Is building an NFC payment app without a secure element like Apple Pay fundamentally insecure?

Suppose I work for a bank and am asked to write an NFC payment app for the iPhone 6 or Android but not use Apple Pay. To simply send the credit card details to the reader via NFC. Now assume I'm not ...
1
vote
1answer
63 views

Encrypt pdf by the server to prevent printing and copying

We are building a portal where users can upload few materials. we have been successful in using the command lines of linux to convert doc,ppts to pdf directly through the server but we are not able to ...
2
votes
2answers
126 views

Receiving sensitive data uploaded on a Web server, and remotely accessing it without exposing it to theft

Edit: I mostly used my university's guidelines on how to meet DPA standards and their own. I extrapolated a bit because encryption on a VM hosted by my uni that is already probably encrypted makes ...
3
votes
2answers
39 views

Preventing/Detecting forgery of logs generated in a potentially hostile environment

I have an application that runs on some host machine and generates logs. Later in the day those logs are securely transmitted to my machine. The problem is that while the logs are being generated I ...
1
vote
3answers
159 views

Encrypting a huffman encoded file

I wrote a huffman encoding program that can compress and decompress files. The file contains a header which contains information that allows me to retrieve the huffman tree. I wanted to add a simple ...
0
votes
2answers
98 views

How to transfer securely a file between servers?

Let's say I have two Linux servers. One containing a desktop app database (running on a local network) and a webserver. I want to automatically transfer each hour a database file (with a size of a ...
-2
votes
2answers
61 views

Identifying/decrypting hashed/encrypted data [closed]

This weekend I took part in an security challenge. I had great fun doing it but i found a huge gap in my knowledge that I'm really keen to fill and hope someone here can help get me pointing in the ...
-1
votes
1answer
71 views

Can I test/determine all decryption types on an unkown filetype. I do have the password [closed]

I have a file that's nearly 200Mb. It was reportedly packed/encrypted with Kruptos 2. But it has a .~enc extension. The header of the file is pure gibberish. Running file says it's data running ...
1
vote
2answers
668 views

can I trust Boxcryptor closed source software? Encryption of files for cloud hoster

Boxcryptor https://www.boxcryptor.com is not Open Source. Can I trust this? Is it secure? No government backdoor? Because there is no alternative for OS X and iOS.
1
vote
3answers
79 views

Completely Protected Virtual Folder

I am a Python / C developer currently working on a extremely important piece of software. The details of the code will not be mentioned, and the only place the code appears is on my own hard drive, in ...
0
votes
0answers
64 views

Where to save digital content and prevent sharing?

I've been inspired by the answer to the question here: Location to store an encryption key It gave me a lot to think about. My friend and I are building a website and we've encountered a problem in ...
0
votes
1answer
102 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?
1
vote
3answers
314 views

Is storing the private key and public keys in same directory on server recommended, like OwnCloud does?

Is this recommended or a good/normal practice? I think not. Because I saw that OwnCloud stores all encryption keys in one directory on the server. One directory contains the private key(s) and one all ...
2
votes
3answers
122 views

Securing data on a server

I have a server which has 'loose' physical security (somewhat easy for the entire server to get stolen). For the sake of the question, let's assume that anyone can access the server physically, what ...
3
votes
3answers
531 views

AES encryption do I need to use a Mode?

I am currently working on a file encryption program using Java Cryptography Architecture. My plan is to have a number of encrypted files where each file has a different AES key. To keep track of the ...
2
votes
3answers
282 views

I want to roll my personal cloud hosted Password Manager using pass. How secure/insecure would this be?

I've come to the conclusion that I need to up my security. I currently have a dozen memorized passwords I use for every device and website. I'm against Keypass/Lastpass due to having to trust they ...
1
vote
2answers
59 views

What is the security benefit of Per-File Encryption key architecture?

Are there any security benefits to having a different key(it is encrypted by a master key and that encrypted key is included in the metadata for the file) used to encrypt each file versus just one key ...
2
votes
1answer
283 views

Field-level encryption vs disk encryption for PCI compliance

We are in the process of setting up a PCI compliant server (with Firehost's help). We are using MongoDB as our primary database. I am having some concerns about the encryption, though. Are there any ...
0
votes
2answers
164 views

Encrypting files in .NET?

I am in a situation where I would like to encrypt audio and text files for an application I am working on. I did some looking around and from what I have seen the Rijndal encryption algorithm would ...
1
vote
1answer
930 views

Why is GPG file encryption so much slower than other AES implementations?

Correct me if I'm wrong: When encrypting a file, GPG creates a one-off AES encryption key and encrypts that key using RSA. This is supposedly to take advantage of AES's superior performance when ...
1
vote
0answers
614 views

Brute-Force/Dictionary attack against encypted file using PBKDF2 key derivation

I have been following this very useful post by Thomas. My use case is slightly different. I am developing a mobile application which requires some sensitive data to be stored on the device in a SQLite ...
2
votes
1answer
154 views

Is it possible to use SSH agent for generic data encryption? [closed]

Is it possible to use running SSH agent to decrypt some data (supplied as a string or read from file)?
2
votes
1answer
45 views

Method/program for editing secure files

I'm not entirely sure if this is on-topic for Security.SE, but it doesn't seem entirely off-topic either, so I'll try. :) I keep a couple of (GPG-)encrypted files with more-or-less sensitive ...
1
vote
1answer
71 views

Cryptographic patterns a security risk?

I am writing an application that serialises objects and then saves the resultant XML in an encrypted file. I am using an Initialisation Vector and a Salt both saved in the file for decryption so two ...
1
vote
2answers
156 views

How could police identify digital contraband and charge someone if it's encrypted with keys?

For example, say I am transferring heavily-encrypted DVD/Blu-ray movies/game copies over the internet. However, I am using double or (+) encryption with keys required to decrypt the file using an ...
0
votes
1answer
104 views

File encryption with external key

I want to encrypt a few files on my computer (not FDE). To do this, I'd like to use something that requires having some external usb thing with the key on it plugged into the computer. Price is not ...
1
vote
2answers
145 views

File encryption for a storage API

I'm implementing a Dropbox-like API, and one of my requirements is to have the files stored encrypted on the server. It is not required that the files are made unreadable by the server, only that they ...
3
votes
1answer
220 views

File Vault 1 password from memory dump

I have a osx 10.9 machine with a File Vault1 encrypted user partition. I would like to remove the encryption, but I don't remember the "master key" which is the only way to remove encryption ...
0
votes
3answers
61 views

Security checks on file transfer [closed]

What are the security checks that I can make on a PDF file being transferred between server and the client?
1
vote
3answers
602 views

How does encryption/decryption work when one generate random key?

I am new to this and want to ask a basic question. Suppose I used my password (say "ABC123") to generate a key using the PBKDF2 algorithm (or any such algorithm). For encrypting a file I'll input my ...
1
vote
1answer
5k views

Forgot password to 7-Zip archive

I think I already know the answer to this question, but I thought I'd ask the experts anyway. A few months back, I created a password-protected 7-Zip archive which housed the source code of a simple ...
1
vote
1answer
281 views

Retrieve RAR Password through Extracted File

So I was wondering about something, but for the simplicity, consider this example: You have a file with n encrypted files in it, of which one is called 'Note.txt' You also happen to have another ...
2
votes
2answers
2k views

How secure is EncFS compared to TrueCrypt?

If I choose the paranoia option for EncFS and for TrueCrypt I create containers using the encryption algorithm AES-Twofish-Serpent and the Hash Algorithm Whirlpool. Are both methods equally secure, ...
2
votes
2answers
186 views

Appropriate way to encrypt passwords/financial info?

I am in the process of creating a file/files containing all of my logins/password info for various accounts. In the event of my untimely demise this file would be sent to the appropriate party(s). ...