0
votes
0answers
399 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 ...
1
vote
3answers
408 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
97 views

How to generate Initalization Vectors correctly

I'm working on a project that splits large files into several encrypted fixed-size blocks (e.g. 4KiB). Those blocks shall be used to be stored persistently on a storage device. Blocks are encrypted ...
1
vote
1answer
217 views

How is the FileVault master key protected?

FileVault has the functionality to both allow and disable user accounts from booting up the encrypted drive. Reference: this cnet article. See also the stack exchange question How does FileVault 2 ...
2
votes
2answers
963 views

Explain real world symmetric key encryption

I'm new to cryptography. While reading about symmetric key encryption, it was mentioned that it requires secret key exchange so that 2 parties can decrypt the ciphertext. Now, using some encryption ...
5
votes
2answers
651 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 ...
2
votes
1answer
159 views

AES + CBC to encrypt individual local files, fixed IV?

I am using AES and CBC to encrypt a local files separately. I don't plan to transmit them over any network. What are the risks of using a fixed IV for my encrypting application? The only problem I ...
0
votes
1answer
217 views

Should I run my password through Bcrypt before using it for encrypting a file with AES-256? [duplicate]

I need to encrypt a file with a password that can be memorized. So I was thinking about running the password through some rounds of Bcrypt before using it for AES encryption, so every time I want to ...
-3
votes
2answers
88 views

Any good products that could crypt the files stored in laptops? [closed]

Thefts of laptops have become very common at my place, and losses of sensitive information is a a major concern for my businesses. So I wonder if there is any good products out there that could crypt ...
3
votes
1answer
385 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 ...
-1
votes
1answer
174 views

About important hacks in history [closed]

I would like to know how important hacks happened, because I can figure out how they hacked a website but I can't figure out how did they hacked into NASA International Space Station source code. Or ...
0
votes
1answer
493 views

How does FileVault 2 work with multiple decryption keys?

With FileVault 2, you can encrypt the hard-drive such that users on the computer can decrypt it with either of their passwords How does this work?
12
votes
5answers
4k 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 ...
3
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 ...
12
votes
4answers
466 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 ...
10
votes
5answers
534 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 ...
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 ...
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 ...