Encryption is the process of transforming plaintext using a cipher to make it unreadable to anyone except those possessing the key.

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How to securely derive a second password specific to an user

I'm giving each of my users an unique Blocktrail wallet that is protected by two API keys (which the server knows) and one passphrase (unique to each wallet). I want the wallet's passphrase to be ...
1
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1answer
30 views

Machine readable, user non-readable - XML file

I need some advice as I have been unable to find anything useful via the web - (Google search). I have used the application EventGhost so as to create a custom shell, that I run using the Windows 7 ...
35
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3answers
37k views

Is 7-Zip's AES encryption just as secure as TrueCrypt's version?

The main difference being TrueCrypt creates containers and 7-Zip encrypts the file itself, so file sizes can be guessed. Now let's just talk about the strength and breakability of the encryption. ...
4
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4answers
9k views

Is diskcryptor really secure?

Diskcryptor is an open-source competitor to TrueCrypt for Windows. It has an edge over Truecrypt for system encryption, because it allows for more than one independently encrypted system partition, ...
5
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2answers
156 views

How to securely store application data on mobile device

How can security be enhanced to the maximum in a messaging app storing messaging history on the device (like whatsapp)? I am specifically referring to methods to minimize the risk of the data being ...
0
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0answers
21 views

Create Incremental/complete backups from a disk encrypted using TrueCrypt? [migrated]

I have a tricky question about whole disk encryption and its backups particularly TrueCrypt for which I have never found a great answer What method do you recommend/use for create automatic backups ...
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1answer
77 views

How to determine if mail was encrypted during transport using the header information?

First things first: I know about the difference between end-to-end-encryption and transport encryption. Back to topic: I already read some things about how mail server handle transport encryption, ...
2
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2answers
216 views

My Virgin Media account password is visible in plaintext to call center staff. What do I do?

Whilst on the phone to support staff (about billing) to Virgin Media, perhaps the largest ISP and telecoms company in the UK, I was asked to confirm my password over the phone. I asked the advisor ...
1
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1answer
94 views

Check HMAC after completing decryption or before?

I have written a piece of software that symmetrically encrypts big files (multi-megabyte). Plaintext is encrypted, after the encryption the HMAC is calculated and written into the header of the file. ...
3
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1answer
105 views

RC4 encryption of torrents safely

Torrent clients offer encryption of traffic using RC4, and people consider this very safe to hide traffic information from ISP. Now since I have a website with SSL encryption, I know that RC4 has a ...
1
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2answers
154 views

Is there a way to securely store unsalted passwords?

So, obviously I'm not talking about username/password pairs here, I plan to store passwords with two salts and three hashes, but what occurred to me is that if I had a table where I kept pairs: ...
4
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3answers
375 views

How can I secure the secret key?

I am a bit confused about securing the secret encyption key. Here is the scenario: I need to encrypt some data (file) This data will be read by a program (say written in C/C++). Both the program ...
2
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0answers
31 views

Security implications of providing an encryption/decryption oracle

I need to provide a service that acts as a symetric encryption/decryption blackbox : the box get a secret key k users send datas d, and get ciphertext c = Encrypt(d,k) users send ciphertext c, and ...
0
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1answer
32 views

Getting multiple key matches on plaintext/ciphertext pairs in double DES

I'm trying to implement a Meet-in-the-Middle attack and just to test it out I've done some hardcoding of values, which is simply this block of simple code: byte[] key1 = new byte[] { 0x20, 0x00, ...
1
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0answers
33 views

Is there a solution for On-the-fly-encryption with active directory rules & policies?

I am looking at having our servers' sql databases for a few program and documents to be always encrypted on the HDD, but available to AD users. So one or multiple users with the right AD privileges ...
2
votes
1answer
82 views

How to send an encrypted mail only knowing the PGP fingerprint?

How does one send an encrypted email with PGP, when he only has the recipient's fingerprint? I am already sending emails using PGP, but I've just pulled a contact's PGP fingerprint who I need to ...
0
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2answers
207 views

Is it safe to auto-fill credit card numbers using Chrome?

Is it safe to auto fill credit card numbers using Chrome? Does it safely store the credit card information? As far as my understanding goes, it just shows asterisk values but on click it reveals the ...
1
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1answer
159 views

Hidden OS: Decoy OS ≠ Hidden OS?

I wanted to use two different OS then two OS equal in the distinct functions: Hidden OS: Linux Decoy OS: Windows Has how? because what I have read until today were processes done with even OS, I do ...
3
votes
1answer
260 views

Hashcat, finding out the Hash [closed]

I've been searching but I can't seem to find the much information on how to extract hash's from say PDF files or Lotus Notes files that I can then use in Hashcat? I know how to get them for Office ...
0
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1answer
96 views

Is it secure to not expire keys in symmetric encryption?

Note that this question describe hypothetical case, that is never meant to be used in real world. Server communicates with clients with message structure: client_id, initialization_vector, encrypted ...
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2answers
47 views

AES algorithm encryption time

What is the time taken by an AES Encryption algorithm, with a key of 128 bits, operating on a normal computer (say with Intel i7) and what will be the impact be on the time if I wish to use a 256 bit ...
3
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2answers
308 views

IPhone iOS 8.3 encryption security against physical access

Excerpt from Apple's Whitepaper "iOS Security" on Effaceable Storage: A dedicated area of NAND storage, used to store cryptographic keys, that can be addressed directly and wiped securely. ...
3
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3answers
7k views

Chrome showing cryptography as 'obsolete'

Similar to this question, Chrome is showing the connection cryptography as obsolete. Opera, IE and Firefox seem perfectly fine with the connection. My guess would be the message authentication is ...
1
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1answer
49 views

CryptoAPI to CommonCrypto with RC4

I have cryptographic code used in the Windows platform, which uses the Crypto API functions and need to convert this to using Common Crypto on OS X. Essentially the original code is this, with error ...
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0answers
42 views

Theoretical VPN and Tor Encryption Chain

Okay, so I've been looking around at the benefits of using tor to access you vpn and vice versa. Here's what I've come up with: VPN -> Tor Pros: Hides Tor usages from isp Hides your activities ...
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1answer
60 views

what is the best security application to check if someone has copied my files with a usb and how to stop that [closed]

I need an encryption application that will detect who has accessed my files from my laptop via a usb and also to help me block memory sticks to access my files and laptop without my permission.
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0answers
46 views

Encrypted Drive. Forgot password. Remember parts of it. Less than 15 characters [duplicate]

So I forgot my password to an encrypted drive (encrypted via Truecrypt 7.1a) and I remember parts of it. I know that there's "12345" in it and the entire password starts with J. how do I restore it ...
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1answer
83 views

Is this process a secure way for users to login? If so, is there a name for it already?

I thought of this process specifically to stop "man in the middle" attacks and replay attacks: User types their username into the client application. Client application sends the username to the ...
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0answers
43 views

Is there an encryption scheme that allows an auditor to view some, not all data?

I want to create an online chat room allows for privacy, freedom of speech, and for law enforcement to protect citizens from violent behavior. I think the best approach is to use Shamir secret ...
4
votes
2answers
94 views

Can the intended recipient be derived from a public-key encrypted ciphertext?

Assuming you have a list of possible recipients' public keys, and a ciphertext encrypted with one of those public keys, would it be possible to determine which public key?
2
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2answers
109 views

Is it possible to encrypt a download twice, once with a different encryption method?

So without giving too much away, the basics are that I have a board that needs an operating system, so I go to an IPL server to supply that operating system. I have a verifier in the middle and my ...
1
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1answer
86 views

Reversing encryption by analysing executable

I have a program that reads data from a file, parses/organizes it, and spits it out as an encrypted XML. The application can also take an encrypted XML and spit out the original file. My objective at ...
5
votes
4answers
276 views

Which strategy to encrypt data accessed by multiple users?

I need suggestions to design my database architecture (in the context of a web application) on the particular point of its encryption ; knowing that the following elements must be respected: 1- Data ...
3
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3answers
632 views

Sending an encrypted PGP email to someone who doesn't yet have my public key

Suppose I have the public key of a recipient I'd like to send an email to, and I've never sent this person an email before. Does it make sense to encrypt my first email to this recipient and also ...
2
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1answer
104 views

Security of online storage of KeePass-like files

A common advice for storing passwords is to store them into an encrypted file, for example by using a dedicated software such as KeePass2. To keep this file in sync between several computers, the ...
27
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2answers
18k views

where to store a key for encryption

I am looking for a way to store a key used for password encryption. I am using a mysql db which would store a user name and an encrypted password that would be encrypted using ...
33
votes
3answers
8k views

symmetric encryption session keys in SSL/TLS

This question concerns the session send and receive keys used in SSL/TLS protocol. my understanding is that this key uses symmetric encryption (DES, AES, BlowFish, etc.) I'm wondering, if ...
1
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2answers
179 views

Storing encrypted information in database vs partition encryption

Trying to search for answers like Database encryption or filesystem encryption? but did not found what I need. My database contains confidential information. What is better? To store encrypted ...
11
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3answers
15k views

How is 4G LTE encrypted?

After a few quick searches for 3G security I was able to learn that this standard uses the KASUMI block cipher, of which several weaknesses have been identified (although apparently none of practical ...
0
votes
1answer
22 views

Size of initialisation vector and plaintext in CBC mode

If I have a 16-number sequence (7,7,7,....7), and I need to encrypt this using a simple 4-bit substitution cipher, do I have to "chop" the plaintext in blocks which are of same size as the IV? In my ...
10
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2answers
365 views

Are there any meta-formats for crypto?

Are there are any (properly specified) meta-formats / schema formats for describing cryptographic message structures? I'm looking for a way to describe the format (where some channels might want ...
1
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0answers
34 views

Possible vulnerabilities in private chat application implemented using web broadcasting

I have never used web-sockets but I am working in a PHP framework which has builtin broadcasting facility. This broadcasting use web-sockets technologies named Redis and Pusher. The workflow of this ...
0
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2answers
48 views

encryption protection against lost password

Here is a plan I am thinking about. I haven't seen this proposed, so I thought I would ask about it. Threat we are guarding against: A lost or stolen laptop leading to exposure of sensitive ...
2
votes
1answer
40 views

Personal cipher/digest preferences ignored when generating a new key pair in GnuPG

I have specified personal digest preferences in my ~/.gnupg/gpg.conf: personal-digest-preferences SHA512 SHA256 SHA384 SHA224 SHA1 then, I have generated a new key pair. But when I check the ...
2
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3answers
179 views

Is it possible to encrypt an SD card?

In the film "Citizen 4", it's said that we cannot encrypt an SD card. Do you know why it would not be possible?
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2answers
95 views

I forgot my 7z password [closed]

I used 7zip to encrypt a 200mb archive of my code used a combination of some of 7 possible words and no numbers or caps. So 823543 possible passwords. What is the best free program I can use to ...
8
votes
6answers
2k views

Why do we keep our keys secret, rather than our algorithms? [duplicate]

On almost any website that relates information about cryptography in general there is this common notion that almost all encryption/decryption algorithms should use a key as one of their inputs. The ...
2
votes
2answers
2k views

What are the vulnerabilities of using a 256 bit encrypted PDF file over email?

I often send confidential documents to others using encrypted PDF files (i.e. files with a user password, and typically with an owner password as well) to prevent both accidental forwards and ...
0
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3answers
378 views

How strong is a simple XOR encryption with random IV?

I'd like to implement some kind of simple (yet as strong as possible) encryption for my client-server application network traffic. Data to be encrypted can be both textual, and binary. Now I'm ...
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1answer
77 views

Does Server Mistrust improve security? [closed]

By server mistrust, I mean the fully implemented lack of customer plaintext on a vendor's system, and lack of vendor access to customer plaintext. Specific case in question: Password and SSH key ...