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.

Filter by
Sorted by
Tagged with
0
votes
1answer
220 views

What is the fuss about 'dot blockchain' and music metadata? [closed]

and how does it work? http://wmot.org/post/music-money-and-metadata-promise-blockchain#stream/0 claims that this is an answer to the metadata woes of the music/recorded media industry. I don't see ...
1
vote
3answers
283 views

Can multi-encrypted file be decrypted with one password only?

Let's say I have a single file I want to encrypt with AES and I encrypt it twice (first encrypt the unencrypted file, then encrypt the encrypted file again). The first time I use password 'ABC', the ...
2
votes
0answers
235 views

Conforming to best practices in password file (keyring) encryption

In order to implement a plaintext password file safe (keyring), while adhering to best Crypto practices today, I came up with this scheme: A user's master password is hashed with Argon2 (\$argon2id\$...
2
votes
0answers
584 views

AES OCB with Argon2 KDF for keyring file encryption

I've just released a python keyring companion package to encrypt the passwords in a file, available here. Description The project is mainly targeted to provide a sufficiently secure storage for ...
9
votes
1answer
6k views

What is a safe maximum message size limit when encrypting files to disk with AES-GCM before the need to re-generate the key or NONCE

The general limits from the NIST recommendation are as follows: Maximum Encrypted Plaintext Size ≤ 239 - 256 bits; Maximum Processed Additional Authenticated Data ≤ 264 - 1 bits; This stack ...
2
votes
1answer
853 views

Can I use a deterministic NONCE for AES-GCM file encryption if I generate “fresh” keys for each encrypted file

The NIST specification states that the deterministic NONCE(IV) should be 96 bits. It should consist of two fields: fixed field of 32 bits and a 64 bit counter. The use of a random 96 bit NONCE is ...
6
votes
1answer
597 views

Derivation of many (Key, IV) pairs from random 128 nonces and one secret 512 master key

The ext4 encryption system encrypt files with aes-256-xts. Each file uses two unique keys which are derived from a 512 bit master key and a per-file 128 bit nonce randomly generated when the file is ...
1
vote
1answer
95 views

Warding an ECIES setup against MitM: ECDSA?

Is it necessary/appropriate to digitally sign an ETM file in an ECIES context? The encryption mode is CTR(using Inferno). The current output is: [shared public key] [ciphertext] [MAC]. The encrypted ...
0
votes
1answer
277 views

Implementing Inferno's ECIES: Creating a symmetric key from sender's public key [closed]

I'm coding(in C#) an offline(no network or server), hybrid file encryption app, implementing Inferno's ECIES. The user's private key is to be stored either on the pc drive or on a usb key, after ...
0
votes
1answer
245 views

How to effectively apply combination of Block and Stream Cipher?

I have used TrueCrypt but it uses a cascaded encryption. I want to know about encrypting a file using two ciphers with each cipher having different key. Cipher A (Block Cipher) - with Key KA Cipher ...
9
votes
4answers
2k views

Does exposing algorithm, key size and IV weaken the security?

I am using an encryption program to encrypt my documents. Previously I have used PGP and AxCrypt, so I just wanted to see how this new tool encrypts the file. This tool is keeping parameters like ...
9
votes
3answers
20k views

Best way to generate a IV for AES-CBC when encrypting files?

The situation is that I want to use symmetric encryption to store some info in files. I'm going to use AES-CBC algorithm. The user is going to remember the password (meaning it will not be stored ...
2
votes
1answer
199 views

Is this cascading encryption, and is my security weakened as a result?

I'm trying to understand what is, and what is not, considered cascading encryption. All of the posts and conversations I've read over the past few days discourage the practice, including this article. ...
1
vote
1answer
59 views

Crypto lib that use files instead of passphrase [closed]

I would like to program an application to allow people to encrypt files without using a password or pass-phrase but an arbitrary long file. I'm searching for a library that allows me to safely create ...
1
vote
2answers
130 views

Using what we already know about the data to decrypt it?

Are there any methods or tools out there that let us use what we know about the data in order to crack the encryption? For example let's say I get access to an encrypted database file but I know ...
-1
votes
1answer
1k views

can pdfcrack software crack a 128 bit encrypted pdf file

One day ago,i downloaded a pdf that requires password then i search a software to decrypt the password that's s/w called pdfcrack Then i install pdfcrack and run a cmd in terminal pdfcrack -f ...
4
votes
1answer
301 views

(How) Can we use HOTP for file encryption?

I recently went through the list of available KeePass plug-ins and noticed one that advertises support for HOTP as a means to derive the database key. Now I trust the developer of this plug-in who is ...
-1
votes
1answer
277 views

I homebrewed an algorithm. Is it secure?

This is a bit of a cross-posted question which I first asked at StackOverflow, however I was not satisfied with stackoverflow, so I came here for an in depth answer. I, as they say, "rolled my own ...
1
vote
1answer
672 views

Dangers of using CTR mode for encryption

I know that it is never suggested to use the same key or key/IV pair twice for a stream cipher or for a block cipher operating in CTR mode. Filesystem-level encryption reuses the same key for a file ...
0
votes
1answer
114 views

Considerations on using a single long-term key for file encryption

I'm thinking about designing my own container file format that allows me to store a file in it along with, say, a thumbnail or other metadata. Some of these files are confidential and therefore must ...
6
votes
4answers
4k views

Can elliptic curve (25519) be used to encrypt file?

This is probably a simple question, but I haven't been able to see it stated anywhere. Is it possible to directly encrypt a file (of any length) with some form of EC using the 25519 curve. I know it'...
3
votes
0answers
91 views

Is EFS vulnerable to chosen plaintext attack?

I have some backup files encrypted with EFS, but I lost the EFS certificate--thus I am unable to decrypt the files. I understand that EFS uses the user certificate public key to encrypt the symmetric ...
0
votes
2answers
1k views

Password in first line of file for AES-256 encryption

I'm using openssl with aes-256-cbc encryption to encrypt a file. The password is on the first line of the file and the ...
2
votes
1answer
1k views

Best practises to generate IV for AES-CTR in this scenario

I'm building a cloud storage application that will store files on my servers. I want these files to be encrypted with AES in CTR mode and the key will be always the same. I'm wondering what would be ...
5
votes
2answers
2k views

Would it be better to split a file and then encrypt, or vice versa?

Assuming that you are paranoid before storing your file (distributed across a shared location), which will be the best case scenario: splitting the file first and then encrypting or encrypting first ...
2
votes
1answer
73 views

Design for file transfers to a new party

I'm pondering a problem of how to enable transfers of files from clients to people that does not yet have an application/account/keys yet. Here's my current thought for Alice wanting to send Bob ...
2
votes
1answer
2k views

Can a file encrypted with one tool be decrypted with different tool? [closed]

I'm new to cryptography and I'm trying implement a file encryption feature into a Python program but I'm running into a big issue...what is needed for someone else to decrypt the file?! Obviously, I ...
2
votes
1answer
2k views

What is required to decrypt an encrypted file?

At the risk of sounding stupid and being laughed at...I must ask this question. What is required to decrypt an encrypted file? Obviously you need the appropriate key to decrypt, but is any other ...
1
vote
0answers
61 views

research on Encryption for master [closed]

I'm tring to choose an way for an Encryption mothod for my research? So,I want to choose one-layer encryption or multilayer encryption,and I want it to be easy to applicable. when I search about it, ...
6
votes
1answer
2k views

Is ChaCha20 alone sufficient for securing data-at-rest?

I wonder if ChaCha20 alone is sufficient for securing files stored on a disk or should Poly1305 should be used along with it? AFAIK, Poly1305 is used to secure the authentication channel, but for ...
8
votes
4answers
2k views

Switching between AES and a highly performant algorithm

I want to de/encrypt several binary files rather frequently on a normally battery-powered device. My goal is to use AES-256 when the device is AC-powered and a highly performant algorithm when it's ...
3
votes
1answer
804 views

File encryption with AES CTR mode

I understand that encrypting files in CTR mode is not perfectly safe, because it potentially leaves the files open for cryptanalysis, if the attacker has access to previous versions of the same files. ...
12
votes
4answers
9k views

Is it possible to get an RSA encryption key by comparing the unencrypted and encrypted file?

Exactly what the title says. If I have a RSA encrypted file, and the exact same file but decrypted, can I tell the key that was used from that information?
1
vote
1answer
109 views

Encryption algorithms larger than 256 Bit for “big data” encryption?

I'm somewhat new to encryption. When looking at encryption programs for big data, I frequently see a maximum of 256 bits. Why do we generally restrict our (symmetric) keys to 256 bits? Can more ...
0
votes
1answer
192 views

Encrypt a file for multiple persons with different keys?

I thought a problem and want to ask if there's a more elegant solution. The scenario: A company with a fileserver, which hosts encrypted documents. The files need to be accessible by about a dozen ...
0
votes
1answer
729 views

Why does rsyncrypto require a public key during decryption?

I recently came across a project called rsyncrypto that sacrifices some security so that you can have rsync-friendly files. My understanding is that it works by generating a symmetric key for each ...
1
vote
1answer
2k views

Encryption of exe file

I recently started learning cryptography. I have learned some basic stuff. I'm also started learning about pc security, so I was wondering how do hackers use cryptography for bypassing antivirus ...
3
votes
1answer
116 views

What is the right notion of security to use for file encryption?

It seems that several file encryption systems do NOT use authenticated encryption. (E.g. gpg --symmetric and boxcryptor as far as I can determine). I understand that this is generally considered ...
4
votes
1answer
520 views

How to securely store data? / How to securely encrypt a file? [closed]

How do I safely encrypt a file? or formulated differentely: How do I safely store the data of my application in a file? Note: Using established tools isn't an option for this. The tasks need to be ...
2
votes
1answer
2k views

Encryting data with password for local storage using libsodium

I want to encrypt data that is stored on the hard disk using a user-entered password. For this I look into the sodium docs and all I can find for symmetric encryption is authenticated encryption. ...
1
vote
1answer
3k views

Given an encrypted file, what are possible ways to find its encryption algorithm?

Given an encrypted file, what are possible ways to find its encryption algorithm? Heuristic ways are okay as well.
1
vote
3answers
145 views

Question about decryption

I have a question about decryption. Let's say I have a bunch of files that are encrypted. Someone gains access to those files, and finds out that he already has one of them, unencrypted. My question ...
1
vote
1answer
3k views

What do I use as the encryption key and initialization vector in AES cfb128

I'm writing a program that can encrypt a file using AES cfb128 (using Openssl and C++). The scenario of the program is this: Person A visits computer, encrypts a file they make, takes away a key (on ...
0
votes
1answer
5k views

Decrypted RSA 64 bit encryption using modulus and private exponent. Got gobbledygook [Verify] [closed]

As part of an experiment, I was given a .enc RSA (encrypted) file that was most likely generated using openssl. I had the public key, I factored it, obtained the private exponent, and decrypted the ....
1
vote
0answers
707 views

FileVault AES-XTS decryption with cipher text that's missing a part

My mac was recently upgraded to OS X Yosemite and FileVault2 full disk encryption was turned on. Encryption finished, but things went horribly wrong and key parts of the disk are filled with all 0s (...
16
votes
2answers
62k views

Twofish vs. Serpent vs. AES (or a combo)

I've seen some posts and info online, but they are from 2009, 2010, 2011 or 2012, which is 3-6 years ago, which is a very long time. So I'm looking for an up-to-date answer about which of these is the ...
3
votes
1answer
2k views

ccrypt and its security

I would like to know how secure is ccrypt to encrypt files (like images, videos and other non-plain text data) using single password of 20+ chars length. It uses Rijndael with 256-bit block size and ...
16
votes
1answer
15k views

Is CAST5 still a secure algorithm to use?

I just installed GnuPG for Windows. The documentation says the default symmetric cipher is CAST5. In PGP also, default cipher was CAST5. Is CAST5 secure to use? Any known attacks reported on this ...
2
votes
2answers
285 views

Does key derivation with known parameters add any security?

First up: this is a question about a concept that I try to wrap my head around; it is not about the specific implementation. Anyway… I have the following scenario (simplified to show the problem I ...
-1
votes
4answers
4k views

Secure way to encrypt and decrypt a folder on Mac or Linux? [closed]

I am looking for a way to securely encrypt files on Mac and Debian. OpenSSL comes pre-installed on Mac OSX and Debian/Ubuntu. Therefore, is this a safe/recommended way of encrypting individual files? (...