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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OS with encrypted RAM?

Are there any applications, JIT frameworks or operating systems that focus on encrypted virtual memory, or perhaps virtual machines that do something similar? I know there are processors (albeit old, ...
13
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2answers
3k views

GPG File size with multiple recipients?

If I encrypt a file for multiple users how does the file size change? Does the size of the output double for two users. How about 10 or 100 users?
15
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2answers
3k views

What's wrong with storing private keys in the cloud?

I know this sounds like a dumb question, but whats wrong with it? Assuming that all private data is encrypted (by the client) using PBE AES256, then is this scheme more vulerable than storing keys on ...
14
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9answers
6k views

Encrypting email for gmail

My friend who is an accountant was asking me what the best way to exchange documents with clients. He was trying to tell me that just sending via email was sufficient and I told him he was insane. I ...
2
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2answers
680 views

Using AES with a hex key/iv, what mode of operation is the “most secure”

I realize that is a loaded question, but it is not an unreasonable one. given a hex key/iv, what mode of operation is most secure from offline attacks. I defaulted to aes-128-cbc. Partly because of ...
20
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4answers
4k views

What are best practices to adhering to HIPAA encryption requirements?

As HIPAA's language is somewhat vague when it comes to actual technical requirements, what are best practices for PHI encryption for HIPAA compliance? I've seen varying levels at different ...
4
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2answers
289 views

When unlocking an encrypted drive, how does the unlocking program know it was successful?

This is very similar question to: If someone breaks encryption, how do they know they're successful? Basically, the answers to that question is that an attacker doesn't know when decryption was ...
28
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5answers
12k views

Why AES is not used for secure hashing, instead of SHA-x?

As far as I understand, AES is believed to be extremely secure. (I have read somewhere that it would certainly not be broken in the next 20 years, but I am still not sure if the author was serious.) ...
2
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1answer
771 views

What browsers support encryption or decryption using local certificates, or smartcard readers?

I am working on a cloud-based solution and I would like to encrypt / decrypt the data locally using either a SmartCard or local Machine certificate. I'm hoping to do this in Javascript, but may ...
5
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2answers
1k views

Is a JavaScript implementation of AES any less secure than other language implementations?

There are a few JavaScript AES implementations available such as Gibberish-aes So assuming the AES algorithm has been implemented correctly in this library then it should be as secure as any other ...
29
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4answers
21k views

How does PGP differ from S/MIME?

Is S/MIME an abstracted system for general MIME type encryption, whereas PGP is more for email? Why would I want to choose one over the other, or can I use both at the same time?
2
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2answers
474 views

How secure is Goodlink for mobile phones when compared to Activesync?

Some of our more technical users are arguing to use Activesync for their phones, while the corporate standard is limited to Blackberry and any device that supports Goodlink. One argument is the ...
5
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1answer
274 views

Can wildcard certificates hide/obscure the hostname in a TLS connection?

I'm trying to increase security for my cloud-based / multi-tenant environment. I'm considering having clients access an obscure URL such as GUID.myCloud.com. I will then respond to that guid-based ...
7
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1answer
684 views

Should I include a random padding in every HTTPS request and response?

According to the following paper, it is possible to decrypt HTTPS traffic by inspecting AJAX calls and using the size parameter as a cryptographic oracle. Should I be sending a variable length ...
3
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3answers
671 views

Why have export controls for cryptography?

I've always heard someone justify the means for export restrictions with "it's for governmental control/spying". In most reasonable countries, the justice system asks people to adhere to the "spirit ...
14
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2answers
3k views

What should I know before configuring Perfect Forward Secrecy?

PFS has gained attention in our audit department because of its innate ability to limit our exposure if someone steals our private key. What pitfalls or common mistakes should I be aware of before ...
5
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1answer
837 views

Clarification needed for NIST's whitepaper “Recommendation for Password-Based Key Derivation”

What are some sample use-cases the NIST is supporting in this policy / whitepaper regarding PBKDF2? This Recommendation specifies a family of password-based key derivation functions (PBKDFs) ...
3
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2answers
615 views

Inspecting a TLS Certificate to determine RSA Key Usage restrictions

With regard to this answer, I have a question about Key Usage in an SSL certificate. Most SSL server certificates have a RSA key which is not restricted through a Key Usage extension, so you can ...
4
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5answers
17k views

Is there a simple example of an Asymmetric encryption/decryption routine?

I can understand Java, Perl and JavaScript code very well. The rest, I have not studied, but I guess I could figure out how to read/translate. I would like to know what the simplest of Asymmetric ...
25
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5answers
21k views

What ciphers should I use in my web server after I configure my SSL certificate?

There are many great questions that ask what is the best certificate to use for a website; but once the certificate is purchased, there is also the possibility to choose or edit the Cipher list. ...
1
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2answers
1k views

SSL Breach - Does the latest BEAST vulnerability mean SSL Issuers now have to worry about integrity? [closed]

Although many SSL certificates have been boasting extravagant guarantees -- typically around $10k minimum to $250k per breach -- to ensure their certificates are valid, to this date, I've heard that ...
4
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2answers
816 views

Which is the easiest secure file transport protocol to implement (SFTP, FTPS, HTTPS, FTP over SSH, FTP over IPsec)

I have to select a secure file transfer protocol, to be implemented in a pre-boot system. I have access to libraries with the basic network functionalities (IP, TCP, UDP, etc...). I might also have ...
5
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2answers
8k views

How can I recover encrypted files after system reinstallation

I had a file which contains images and videos, I was using the windows 7 ultimate and I had encrypted the file. Now I have copied that file to my hard disk and format that operating system and again. ...
12
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2answers
635 views

Is it possible to have a key for encryption, that cannot be used for decryption?

For example, a server might have some encrypted logs or storage or whatnot, that would only be used for reference later. This way even if the server is hacked, everything is still OK until the hacker ...
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5answers
9k views

How to properly encrypt a communication channel between a client and a server (without SSL)?

I have a poor knowledge in the world of cryptography, I'm just starting to learn it so I'm a newbie :) As a project for getting into the field of cryptography I want to write a client\server program ...
2
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2answers
1k views

How effective have statistical methods been at breaking encryption?

If we look at how statistical engines run on-line translators, and how they are built, we see that they look at a new language and run a statistical model over it searching for what's probably the ...
1
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0answers
276 views

Server side data de-duplication + client-side encryption with private key. Possible with “convergent encryption”? [duplicate]

Possible Duplicate: Online backup : how could encryption and de-duplication be compatible? I just saw an article on Techcrunch wherein a startup company was describing their new cloud ...
7
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3answers
792 views

It is possible that brute force attempts are successful before the worst case, correct?

When I read about a password being secure and stating that it would take X amount of week, years, etc. isn't that referring to the worst case? What happens if the brute force method is successul in ...
29
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6answers
31k views

Asymmetric vs Symmetric Encryption

I am currently taking a principles of information security class. While talking about different encryption methods a large number of my classmates seem to believe that Asymmetric Encryption is better ...
4
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2answers
614 views

Protecting data on a laptop with linux

I'd like to keep some private data (photos, notes, ...) and my browsing data hidden. The rest is not so important. Most of the time I just put the laptop to sleep and don't shut it down often, making ...
2
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2answers
905 views

C# Encrypting string in DES 3 CBC mode

Is it normal that when I use Double DES secret key to encrypt a string in DES3 CBC mode then I always get the same cipher text? For testing I'm using IVC=0.
47
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8answers
5k views

Online backup : how could encryption and de-duplication be compatible?

A "soon to enter beta" online backup service, Bitcasa, claims to have both de-duplication (you don't backup something already in the cloud) and client side encryption. ...
5
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3answers
1k views

What is the difference between encrypted data and data sent through an encrypted tunnel

I am looking at different VPN protocols. [1] L2TP does not provide encryption so require IPSec to encrypt the data [2] IPSec tunnel provide encryption to the tunnel What is the difference in terms ...
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1answer
567 views

Android application level encryption cracking

We come across Android applications which use the custom encryption. When we proxy the Android phone or emulator, the proxy captures traffic which is unreadable. Is there a known technique to read ...
5
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3answers
1k views

Is it safe to use different derived keys but from the same passphrase for AES CBC encryption followed by HMAC SHA256 hashing?

I am working on a cross platform (JS/iOS/Android) list manager application that persists data through a REST API and I want to ensure that any textual data is properly encrypted on the client side so ...
5
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3answers
1k views

US export control on open source libraries

I want to ask, is the US export control applicable only to US citizens? E.g. I think Bouncy Castle are Australians. Do use of their library fall into export control regulations? I do not understand ...
4
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3answers
766 views

How are possible uses for X.509 (SSL) certificates denoted?

X.509 certificates can be used for servers, clients, email, code signing and more applications. http://twitpic.com/6gdxaq indicates that a certificate can have different of these 'capabilities' on it ...
8
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4answers
2k views

Is using HMAC to transmit a password OK?

I'm writing a small webapp and I don't want to transmit login passwords as cleartext. As I don't have SSL available I've written a one-time challenge system which sends a random string with the login ...
7
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3answers
463 views

How Reliably do mail systems transmit Encrypted PDFs

We have an solution design that will be sending Encrypted PDF's to our many clients, who will all be using varied email providers. We have tested the pdf's through the usual cast of internet mail ...
16
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2answers
2k views

Flaw in encryption through pseudorandom number stream (from PGP documentation)

I was reading PGP docs and came upon a part written by Phil Zimmermann (PGP's creator) that piqued my curiosity: When I was in college in the early 70s, I devised what I believed was a brilliant ...
22
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4answers
3k views

How would you store a 4 digit pin code securely in the database?

I'm familiar with password hashing, using salts, bcrypt etc. But it doesn't seem like this would work to store a 4 digit pin code since the attacker could try all 10,000 combinations quite quickly. ...
8
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3answers
780 views

Does the SSL encryption strength or validation level of a website really matter?

When looking to get an SSL certificate one is presented with a lot of options. For example lets take Network Solutions since they have a nice comparison chart. Immediately there seems to be 4 major ...
6
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3answers
396 views

Embedded System Communications Security

I am getting ready to start deploying an embedded sensor network that is internet connected (via the cell network) and reports private data on a regular basis back to a central server. Unfortunately, ...
7
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2answers
2k views

What encryption (if any) is used on electronic credit cards?

Out of curiosity: how do electronic Visa/Master Card debit/credit cards with microchips authenticate a transaction? Are they stupid storage for a key which is simply read by a reader or do they ...
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2answers
1k views

Is it possible to encrypt your Java source code and still have it readable & writable in Eclipse?

I have some Java source code on my laptop that would cause me a great deal of suffering if I were to lose possession of the laptop and the source code were to fall into someone else's hands. Is there ...
12
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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 ...
9
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3answers
1k views

Is TDEA (TripleDES) invulnerable to the weak keys of DES?

The key space of DES includes some keys that are weak, which results in a ciphertext that is extra vulnerable to cryptanalysis. Is TDEA (also known as TripleDES) invulnerable to those weak keys? Or, ...
4
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4answers
1k views

AES ECB Mode for single block/random data encryption

I need to save random 16 byte keys to a database. To encrypt these keys I currently use AES 128 with ECB Mode (because of smaller data to store, no IV needed), but now I read a lot about ECB being ...
25
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4answers
15k views

What steps do Gmail, Yahoo! Mail, and Hotmail take to prevent eavesdropping on email?

I would like to ask what happens when an email is sent from gmail, yahoo or hotmail public web email services? I don't understand email protocols in details, but as far as I know email traffic is ...
3
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5answers
534 views

What should one do when he/she wants to protect him/her home--computer--?

As you know, deleting a file by pressing shift-delete or by using the Trash doesn't mean that the file is unrecoverable. It's data persists on your computer. In day to day life, adversaries use ...