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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22
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5answers
2k views

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 ...
21
votes
6answers
32k views

How secure is a Windows password protected zip file?

I need to send some sensitive information to a client. I thought I would email a password protected zip file I created using Windows XP and then call them with the password. Presuming I pick a good ...
13
votes
4answers
5k views

What are you doing when you move your mouse randomly during a truecrypt volume creation?

Is that called a 'round' every time you move your mouse when creating a new volume? I'm talking about the screen with the random numbers during the volume creation process. What is the purpose of ...
12
votes
6answers
13k views

How secure is NTFS encryption?

How secure is the data in a encrypted NTFS folder on Windows (XP, 7)? (The encryption option under file|folder -> properties -> advanced -> encrypt.) If the user uses a decent password, can this ...
12
votes
5answers
5k views

How can I decrypt data with Java, without hard-coding the key?

I hope this is not a chicken-egg problem or reinventing the wheel but here goes. I have a Java application that needs to access a password protected file (actually during the application startup). The ...
12
votes
4answers
494 views

Encrypting data by parts vs encrypting the whole data

Suppose I have a file with records, and I have two options to encrypt it: encrypt the file as a whole encrypt each record separately and store them together. Which way is generally preferable and ...
11
votes
6answers
10k views

Does password protecting an archived file actually encrypt it?

For example if I use WinRAR to encrypt a file and put a password on the archive how secure is it? I keep a personal journal and am thinking of doing this, or is there a better way? It's just one huge ...
11
votes
1answer
14k views

Brute Forcing Password to a Truecrypt-encrypted file with Partial Knowledge

A while back, I encrypted a few files with Truecrypt, and stored the password in my head. Now I need to access it again, the password isn't working. I'm sure most of it is right, but I'm off by one or ...
10
votes
5answers
551 views

Security of using passwords or even passphrases to encrypt files

Is it ever appropriate to use real-world passwords to encrypt files to be sent via unsecure means. By real world, I mean a password that is memorable and memorisable by a mere person? I am implying ...
10
votes
2answers
2k views

How to encrypt data on the server?

I have some data on the server (running Linux) which needs to be encrypted (company policy). This data is being served by an application running on this machine. Now I consider a few possibilities: ...
10
votes
4answers
7k views

What's the standard way to encrypt a file with a public key in Java?

I'm writing a client app in Java that sends encrypted data back to the server. All clients have my RSA public key. Is there a standard way to encrypt a given file with it to send it back to the ...
10
votes
5answers
6k views

Encrypting files in a windows environment

We have certain client data which must be encrypted at all times. The part we have been struggling with is encrypting files on network shares. Currently we have network folders encrypted using PGP ...
9
votes
6answers
9k views

Good file encryption tools

Could you please help me find a good file encryption tool? The target OS is Linux, but tools for Windows are welcome, too. FOSS tools are preferred. The tool must be reliable both for the recovery of ...
8
votes
3answers
1k views

time to crack file-encryption password - more than just iteration

I have often seen that takes x amount of time to crack a certain length password. But this just seems to be the amount of time it takes to iterate through all the possibilities. What about the time it ...
8
votes
4answers
46k views

How to recover a lost zip file password

I have some files I was given by my teacher at University, I could chase him up, but I may as well try getting blood from a stone, his response rate isn't great and I completed my degree a year ago! ...
7
votes
7answers
2k views

Verify the password of an encrypted file without waiting for complete decryption

I am currently working on an application that encrypts files with AES 256. The problem is that I want the user to see whether the password is wrong before the file is decrypted. For example if you ...
7
votes
3answers
269 views

How can I allow acces 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 ...
7
votes
9answers
3k views

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 ...
7
votes
4answers
3k views

when people say a file has a checked md5 hash, what exactly does that mean?

ok I was just reading this site: http://www.zdnet.com/blog/bott/stay-safe-online-5-secrets-every-pc-and-mac-owner-should-know/3542?pg=4&tag=mantle_skin;content and thought of something I always ...
7
votes
3answers
396 views

Secure cleaning of deleted files

So I know how to secure delete files. But at our company, we have a laptop which had many important documents, which now have been deleted, but not in a secure way. We can't perform a full format of ...
7
votes
2answers
4k views

Simple way to encrypt files on Linux and decrypt on Windows?

We are in need of an encryption process for backups of very valuable data. This data will be stored on a distributed filesystem, so even with permissions set right, its not out of reach that this data ...
6
votes
6answers
529 views

Applying file deltas to an encrypted file

I am developing software that will be used for data backup. The server will run on Linux. Security in transportation is not an issue (HTTPS or SSH), but the data must be stored encrypted on the ...
6
votes
7answers
947 views

How do I secure patient data cheaply in a small doctor's office?

I am a single practitioner with 3 work stations and a server. What is the best cost effective way to secure my data and I suppose encrypt it. The gov't wants us to prevent any unsecure access to ...
6
votes
1answer
234 views

Could a consumer-friendly PGP-like file encryption application theoretically be secure?

In a situation where there are desktop and mobile clients, and a central public key repository to and from which the desktop and mobile clients automatically upload and download public keys as needed, ...
6
votes
3answers
4k 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 ...
6
votes
1answer
229 views

Should an app remove or encrypt locally stored user data after a user logs out?

I’ve been poking around in the Application Support folder of a popular app, trying to extract some chat logs. (By “popular”, I mean that most people reading this will have heard of it. I’m not sure if ...
5
votes
2answers
716 views

Designing a cryptographic file-sharing protocol

As a learning project, I am trying to implement a secure way to share files with a friend over dropbox. (I am not looking for existing software, I am doing this in order to learn how to do this ...
5
votes
4answers
4k views

TrueCrypt -vs- MacOS encrypted sparse image - equally secure? Other alternatives?

I'm currently trying to find my personal best solution for storing passwords and other sensible data. Recently I've used 1Password on iPhone and Mac but I'm not really satisfied with its predefined ...
5
votes
4answers
380 views

Is Encrpyting 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 ...
5
votes
2answers
2k views

After How Much Data Encryption (AES-256) we should change key?

Considering AES-256 encryption, what is the maximum amount of data should be encrypted with one key? Does Block cipher modes/IV/counters also governs the limit? If say the maximum amount is 50GB, ...
5
votes
3answers
939 views

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 ...
5
votes
2answers
2k views

Microsoft Office 2013 File Encryption

To what extent can the native file encryption provided by Microsoft Office 2013 (Word, Powerpoint, Excel, etc.) be relied upon to maintain the confidentiality of documents, especially within the ...
5
votes
1answer
87 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) ?
5
votes
1answer
442 views

What iOS apps use data protection?

The iOS data protection API and its implementation are fairly well documented, but it is only really useful if apps actually use some level other than NSFileProtectionNone for their files. Is there ...
5
votes
1answer
2k views

Device versus file based encryption in TrueCrypt for a flash drive?

Are there security tradeoffs to be considered in deciding between encrypting an entire flashdrive with TrueCrypt versus storing a file encrypted container? The security goal is to be immune to the ...
4
votes
6answers
2k 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 ...
4
votes
1answer
386 views

How to encrypt an entire portable HDD, so that it cannot be read/written without the password for it?

I use a portable USB drive (Seagate FreeAgent Go Flex) to keep all my personal stuff, and though the HDD company does offer a password scheme to control access to it, that would work only on windows, ...
4
votes
1answer
1k views

truecrypt second encryption of the master and XTS key with a back door password

this table was published by (Ubuntu Privacy Remix Team ), in an analysis document, anyway i was quite skeptical. On file based containers as well as on completely encrypted partitions or drives ...
4
votes
3answers
1k views

Can email be encrypted before it reaches the mail server? If not, is there something that would allow something like this that's being worked on?

I was thinking about hosting my own email (own email server) instead of using Gmail. But then I realized I could never host my email on a server where I'm also hosting Wordpress. That is because I ...
4
votes
2answers
1k views

What trust level should I give keys I need for encryption?

As I'm encrypting server backups, I typically install my public GPG key from a keyserver into me server's keyring: gpg --search-keys 6569758F I import the key into my keyring. I then attempt to ...
4
votes
2answers
3k views

Recover EFS encrypted folder after wiping system partition

We've recently ran into trouble while reinstalling one of client's desktop computer. Disk was split into two master partitions named C: and D:. We wiped out C: and reinstalled system (Win XP SP2 ...
4
votes
4answers
441 views

How to securely delete a table in MS-Access?

I have a Windows 7 computer which currently has a large working Microsoft Access 2007 database on it containing some tables with confidential data. I would like to securely delete/remove the tables ...
3
votes
3answers
473 views

Encrypting an email server's local drives or filesystems

Planning to deploy a remote hosted mailer (Zimbra based) I need to make sure the local data on the machine is encrypted. Currently, the plan is to use the built in LUKS to encrypt /opt/zimbra and ...
3
votes
2answers
1k views

How to protect from copying files?

Is possible to protect files from being copied if you are the administrator of a machine? I heard that this behaviour is possible: one software developer sells his software in such a way. He installs ...
3
votes
3answers
457 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 ...
3
votes
3answers
880 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 ...
3
votes
4answers
827 views

Apple FileVault — would Apple build a backdoor?

Could Apple build a backdoor into it's FileVault encryption technology? Is that a risk you take of using a closed-source encryption product in general? Would using something like TrueCrypt be more ...
3
votes
2answers
5k views

Can I properly make password-protected 7z archives secure?

After reading the question and answers of this and this, I left with an overall impression from the last one that zips were considered not safe and insecure way of sharing data. I still think ...
3
votes
1answer
391 views

Is there a way to store user files without being able to decrypt them?

I'd want to build a secure file storage web application. Currently ordinary password authentication is used for login. After login this password is used for encryption and decryption of user files at ...
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 ...