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

learn more… | top users | synonyms

12
votes
2answers
1k views

Protection of Keys/Passwords on Virtual Hardware (XEN, KVM, VMWare, etc.)

Is there any reasonable way to secure data on virtual hardware? What I mean by "virtual hardware" is the various hosted systems that one can rent from various online hosters, that run on top of XEN, ...
12
votes
2answers
2k views

How are mobile telephony networks like LTE and HSPA encrypted?

How are mobile telephony networks like LTE (4G) and HSPA (3G) encrypted? between what parts is the communication encrypted? who has access to the keys? is symmetric or asymmetric encryption used? is ...
12
votes
0answers
859 views

MPPE-Send and Receive key derivation from MS-CHAPv2

I am trying to get the MS-MPPE-Send-key and MS-MPPE-Recv-key from the MS-CHAPv2 challenge material. I am able to follow the RFCs 2548 3078 and 3079 to the step of getting the GetNewKeyFromSHA() it is ...
11
votes
5answers
3k views

Confusion: Why isn't a passhrase encrypted SSH key two factor auth?

I'm trying to figure out the best practices for accessing my devbox from a public terminal. Most sources I've found recommend protecting the box with some kind of two factor authentication, such as ...
11
votes
7answers
7k views

Who tells that TrueCrypt is secure?

Assuming you're not running on a compromised machine and you're following common recommendations (long random passwords, etc.), who specifically (name and affiliation) asserts that TrueCrypt is ...
11
votes
7answers
3k views

What's the safest way to transmit a message to another client through a server hidden from high level malicious users? [closed]

Suppose you're constantly being menaced by high profile hackers and agencies that try to intercept messages sent between you and a friend. The question is: what's the safest way to send messages to ...
11
votes
5answers
647 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 ...
11
votes
4answers
2k views

Using computer random number generators to produce keys, it is secure?

Does generating an encryption key using the random number generator on one's computer present a security risk? If so how might that risk be mitigated, specifically when generating RSA key pairs in ...
11
votes
5answers
4k views

What is the benefit with using encrypted RAM Memory?

I sometimes hear that encryption is used for the RAM Memory, but I don't really understand why this is needed. Why is RAM Memory needed to be encrypted? and is this done by the hardware, the ...
11
votes
4answers
1k views

What kinds of SSL certificates are usable for encryption?

I know that Verizon SSL certificates cost close to $600. There are couple of cheap alternatives, but I never really understood why Verizon does not offer such certificates. Look for RapidSSL at ...
11
votes
3answers
936 views

OpenSSL generates 1032bits when I request 1024bits

When I enter the command-line openssl dhparam -text 1024 the resulting safe-prime is 1032 bits instead of 1024 bits. It seems like the 1st byte is always 0. Why is this?
11
votes
5answers
4k views

How can encrypted traffic bypass the Great Firewall of China when it is being blocked?

The Great Firewall of China is controlled by the government and has put in place a "learning algorithm" to block unapproved encrypted traffic. The only way to get encrypted traffic through the ...
11
votes
5answers
846 views

what would be a good way for a doctor to send xrays encrypted to another doctor?

As a dentist, I often want to send medical information including digital xrays to another doctor. What would be a good/easy way to do this encrypted? Our organization currently requires that all ...
11
votes
5answers
3k views

Storing private asymmetric key in application binary?

I would like to give a daemon-style process (i.e. no user interaction) access to a shared secret key so that it can access a shared, encrypted data file. User applications accessing the same encrypted ...
11
votes
3answers
11k views

Choosing a session ID algorithm for a client-server relationship

I am developing an application which has a client-server relationship, and I am having trouble deciding on the algorithm by which the session identifier is determined. My goal is to restrict ...
11
votes
1answer
3k views

Truecrypt compromised? (Coldboot attack)

In light of recent developments in computer forensics and "password recovery" utilities, can encryption technologies such as TrueCrypt still be relied on for a high degree of protection? It would ...
11
votes
5answers
3k views

Is it worth the effort to store FTP passwords encrypted?

I have a project to build a system that needs to push files to multiple third-party FTP servers. I have asked these third parties to provide a more secure interface; all have declined. So now I have ...
11
votes
1answer
5k views

When using AES and CBC, is it necessary to keep the IV secret?

If I encrypt some data with a randomly generated Key and Initialization Vector, then store all three pieces of information in the same table row; is it necessary to encrypt the IV as well as the Key? ...
11
votes
5answers
16k views

Can Skype chat be protected from snooping? Are there safe alternatives?

I use Skype a lot. With all of my clients, staff, contractors and friends, however, the acquisition by Microsoft worries me, as two of my clients are direct MS competitors, and I often work on long ...
11
votes
7answers
4k views

Why can an encrypted private key be brute forced?

When using SSH keys to authenticate to a server for remote access, why is it possible to devise the true key and therefore the passphrase from an encrypted private key, without checking each guess of ...
11
votes
1answer
8k views

What changed between TLS and DTLS

What did the DTLS (TLS over UDP) authors have to change so that it could run without TCP? Bonus points: Do any of the protocol difference affect the way it should be used, both in terms of interface ...
11
votes
1answer
1k views

Native rsync protocol security

Is the native rsync protocol (port 873) secure? Does it encrypt data or credentials? I'm planning on using rsync to store encrypted files in the cloud, I'm wondering whatever the password is ...
11
votes
2answers
6k views

For LUKS: The most preferable and safest cipher?

I'm about to encrypt two of my hard drives using LUKS, since I can't really do it myself I use the guide on the Arch Linux wiki (which can be found here). In an example in the guide the cipher ...
11
votes
2answers
3k views

Which cipher suites with AES cipher provide forward secrecy?

Does standard AES with RSA (reported by Opera as TLS v1.0 256 bit AES (1024 bit RSA/SHA)) provide perfect forward secrecy? Which SSL3.0 and TLS1.0 ciphers do provide forward secrecy? Which ciphers ...
11
votes
4answers
3k views

Is it feasible to encrypt customers personal data? (name, address etc…)

Seeing the Sony Personal data kerfuffle unfold has gotten me thinking about the encryption and securing of personal data - obviously credit cards can (and should) be encrypted, making data breaches of ...
11
votes
1answer
2k views

Why can't I use the same key for encryption and MAC?

I wrote a simple file encryption program as an example of how to do encryption correctly, but after reading a questions about encryption + MAC, I think I made a mistake by using the same key for both. ...
11
votes
4answers
8k 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 ...
11
votes
3answers
8k views

How (in)secure is POP/IMAP/SMTP

I'm making a few assumptions about basic email security, and I want to confirm or clarify some of these points to make sure I understand the big picture. Please correct me where I'm mistaken: The ...
11
votes
3answers
14k 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 ...
11
votes
2answers
1k views

What role does clock synchronization play in SSL communcation

We've recently implemented WS Trust security over SSL for our client / server communications. Our application is used by thousands of our customers, spread out all over the world. One of the ...
11
votes
1answer
490 views

“Please Enter Nth Character” without HSM

This question has been asked a few times, but always in the format "How does examplewebsite.com implement their 'please enter xth yth and zth characters of your password' function?" And the ...
11
votes
1answer
792 views

Any risk in using the same salt for several hashes on a user?

Right now I'm storing a salt and password_hash on the users table (pretty standard stuff). The need arose to get a secure hash of another field for a user. Is there any risk in reusing the same salt ...
11
votes
2answers
1k views

Can a Firefox add-on or plug-in access the user's websites' saved passwords in decrypted mode?

Going deeper into the previous question on Firefox plugins and add-ons malware risks: Could a Firefox add-on potentially decode and capture the encrypted websites' passwords saved in the browser?
11
votes
2answers
3k views

Security of running openpgp.js in a browser with the private key in HTML5 localStorage

If I were to write a web application using openpgp.js (http://openpgpjs.org/) for creating PGP encrypted/signed messages and if I stored the user's private key in localStorage, would this be ...
11
votes
1answer
266 views

DNSSEC signing algorithms

Virtualmin supports a flurry of algorithms for DNSSEC: RSASHA1, RSASHA256, RSAMD5, DSA, DH, HMAC-MD5, NSEC3RSASHA1, NSEC3DSA. If I understand correctly, there's Proof of Concept available for SHA1 ...
10
votes
5answers
2k views

Whenever an unhandled exception somehow makes it into production, is it safe, viable, etc. to print an encrypted stack trace to the end user?

Whenever an unhandled exception makes it into production somehow - whatever the reason - there's generally an option (especially with .NET programs) to print out a stack trace to the end user before ...
10
votes
5answers
2k views

Can voice chat be spied?

I wonder if voice chat (via public services like yahoo, google talk, skype, etc) is practically secure? Is it possible for the ISP or any middle point? I do not consider hacking the computers, but ...
10
votes
6answers
2k views

Security of SHA256 and Bitcoins

The Bitcoin network use SHA256 as a core component to it's design. I'm no expert on cryptography, but it seems to me it usually is only a matter of time before security vulnerabilities are discovered ...
10
votes
4answers
3k views

Why does PGP use symmetric encryption and RSA?

Looking into the details of Pretty Good Privacy, I'm confused as to the reasoning behind encrypting the message with a session key and the key with the recipient's public key via RSA. I fail to see ...
10
votes
4answers
509 views

How can I audit which type of Block Mode encryption is being used when no source code is available?

Given that there are clear advantages to using some block modes of encryption over another, and I would like to ensure that all software used in the enterprise uses a certain "level" of security I'd ...
10
votes
5answers
6k views

SSL/TLS - Distinction between self-signed cert and self-signed CA, and other questions?

I have a small personal website which I wish to serve securely over HTTPS. At the moment I do not wish to use a third party CA to sign my certs. I was reading this document on generating a self-signed ...
10
votes
5answers
14k views

What does “key with length of x bits” mean?

I'd like to know what it means to say "the cryptosystem C uses keys with a length of x bits". I do not understand what the bits length means... doesn't it depend on the encoding? The same word encodes ...
10
votes
4answers
9k views

Unlock hard drive vs full-disk encryption

When I turn my notebook on, it asks me for the password to unlock the BIOS and than it asks me for the password to unlock the hard drive. How different is this 'password to unlock the hard drive' ...
10
votes
2answers
518 views

Forward secrecy for kids

In the Scouts, it is popular to use secret codes to write messages (which are simple ciphers). I want to introduce Forward secrecy to the kids so they can use it with these ciphers. So, if the ...
10
votes
4answers
853 views

What is the key when facial recognition is used as a password?

I get the basics of what face recognition is and the fact that it is used to protect PC's and as a login replacement. However, if it was to be used for encryption, where the role of the key is played ...
10
votes
2answers
1k views

How might the U.K. Government's proposed internet surveillance equipment “bypass” encryption?

http://www.channel4.com/news/black-boxes-to-monitor-all-internet-and-phone-data http://rt.com/news/uk-privacy-internet-freedom-186/ 'Black boxes' will be installed by internet services providers ...
10
votes
4answers
3k views

How likely/possible is it that the NSA have broken common encryption techniques such as SSL/TLS?

Jumping on the NSA/Prism questions bandwagon - There's been a lot more attention drawn to facilities such as Room 641A which indicate that the NSA has been, amongst other things, applying mass ...
10
votes
4answers
3k views

Truly deniable encryption

What tools can be used to make truly deniable encryption? Suppose, authorities can use any force to make you open your passwords. Truecrypt can have only one hidden container, which means that ...
10
votes
3answers
2k views

How can I encrypt a file with .NET and have the same file size of the original file?

I'm using .NET and I've written an awesome routine (xD) that encrypts and decrypts a file using AES256 CBC. It works perfectly, but now they told me that the encrypted file must be of the same size of ...
10
votes
2answers
2k views

How does a weakness in a random number generator lead to a compromise of the entire cryptographic process?

In the news, there are several articles (here, here, and the technical point of view) which have to do with a weakness in a random number generator. The question is somewhat twofold. What symptoms do ...