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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2
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1answer
41 views

Is a Linux environment PCI compliant if the swap file is not encrypted and PANs are loaded into RAM?

Is a Linux environment PCI compliant if the swap partition/file is not encrypted and PANs are loaded into RAM by an application?
4
votes
3answers
643 views

Website: Pre-Shared-Key Authentication

We have this web-application with high valuable (business) data. All communication is encrypted through TLS/SSL. While I consider this a really safe protocol, it can still be compromised if someone ...
-1
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1answer
43 views

PHP/Ajax Data transmission security

I'm learning about web security mechanisms. I have developed the following system in PHP and JavaScript: assuming that I have a page named: messages.php which is a real-time chat system. first when ...
3
votes
1answer
132 views

What is the best way to manage gpg keys across multiple devices?

I have a desktop computer and a laptop computer both running Debian. All of the devices have encrypted hard drives. I also have a phone running Cyanogenmod/Android. What is the best way to manage ...
0
votes
1answer
33 views

A folder lock/encryption program that can do this? [on hold]

I am looking for a program that can lock or encrypt folder, but in case if my laptop is stolen and C drive is reformatted and reinstalled, and i have locked folders on D drive, these folders to remain ...
22
votes
2answers
3k views

Break the popularity contest crypto

There is a very interesting puzzle on the Programming Puzzles and Code Golf site to Rearrange pixels in an image so it can't be recognized and then get it back. I understand that this is not ...
13
votes
9answers
7k views

Encrypting files on Google Drive

It's my understanding files kept on Google Drive are not protected. I would like to have them encrypted so that to be able to view or modify them one must enter a password. I foresee a potential ...
1
vote
3answers
271 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
87 views

Klein and PTW wep attack

I'm working on an implementation of Klein's wep attack. For that, I've set up a router with wep encryption and collected 50,000 unique IVs from it. I tried only calculating K[0], meaning - the first ...
0
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1answer
29 views

XTS vs AES-CBC with ESSIV for file-based filesystem encryption

In a blog post I recently read called "You Don't Want XTS," the author explains some of the pitfalls of using XTS to encrypt filesystems. Specifically, he recommends against ever sharing encrypted ...
2
votes
3answers
56 views

VPS Privacy: OpenVZ vs KVM vs Xen

Considering OpenVZ, KVM and Xen: Which VM technology is the most difficult for the host's administrators to access given an encrypted root partition? Can I have a reasonable expectation that rogue ...
0
votes
2answers
66 views

Encryption mechanism

I want to send data over the Internet securely. For that, I am using an public key of the receiver to encrypt the data. In this case, if an intruder in the network modifies the data, like placing the ...
5
votes
5answers
5k views

What is the most secure way for two people to communicate?

There are various services on the internet that offer secure communications. Typically in the past if I want to share some sensitive information with someone, I will do so over a Cryptocat chat ...
1
vote
5answers
242 views

Secure login feature with low CPU power

I'm developing a program that contains a login function in C++. The problem is that I don't know how to develop it in my situation. I want to run the software on a raspberry pi, it only has a CPU ...
15
votes
2answers
9k views

Is it possible to decrypt a satellite TV signal without using a smart card?

And if it is possible, why has it been decided to keep using a smart card for this task? I will be grateful if you can provide some practical examples on how to bypass the use of a smart card (if ...
0
votes
2answers
101 views

Hacking machines using internet packets [on hold]

I have a friend (X) who hacked the whatsapp account of someone (Y) using iphone. He told me that he sent a packet to the iphone of Y that appears as a normal whatsapp message but now he can see all ...
0
votes
0answers
14 views

user defined counter increment function for blowfish CTR in java [migrated]

We did some research but couldn't find the answer. The javax crypto blowfish counter increment function seems to be fixed ( standard inc by 1? ). How to change the increment function, say by 4? Or ...
3
votes
2answers
138 views

Search on encrypted data of multiple users

I want to implement a search over encrypted data. I found a blogpost, which explains 3 methods. One method is to use deterministic encryption, which I'm trying to implement. But my use case is a ...
0
votes
1answer
29 views

PCI compliant transparent data encryption at disk/folder level on windows?

Is there a way to achieve pci compliant data encryption at disk/folder level in windows in a way that is transparent to applications(they must be able to write/read to encrypted folders/disks as if ...
1
vote
2answers
113 views

Is a Diffie Hellman Ephemeral key good material for being used as a symmetric cipher algorithm key?

I am designing a secure protocol (for academic/learning purposes) and I am at the point where I need to (re)design the key exchange step. In my previous implementation, I used to rely on RSA to ...
3
votes
1answer
93 views

Encrypting data within SQLite database in JAVA - How to store key?

So, a bit of context before I start may be handy. I am developing a JAVA desktop application which will use an SQLite database to store/process data. The application will utilize authentication to ...
1
vote
2answers
68 views

Database compromised and some passwords cracked

I run an MMORPG game and today while moving from one server to another, apache failed and listed some of the data on the server including a back-up of all the source code + database which a few people ...
1
vote
1answer
24 views

Importance of password strength with secure element?

Greetings SE security community. Background: I have a number of items like certificates, databases, and encrypted file systems that require private keys. In order to avoid having duplicates of these ...
0
votes
1answer
22 views

How is the Premaster secret used in TLS generated?

I believe that it uses some combination of the random values sent in the hello messages. From RFC 2246: (TLSv1.0) RSA encrypted premaster secret message Meaning of this message: If RSA is ...
1
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2answers
34 views

pci compliance and temporary files

Does storing temporarily a non-encrypted file containing some PANs violate pci requirements? (for example because it is being processed by an application, or to open it on a file editor)
3
votes
1answer
519 views

Encrypt Android app data and send to web service

I want to develop an Android app that may contain sensitive personally identifying information (national ID number, phone number, etc.) among other data that will be stored in an Android phone. Let's ...
0
votes
2answers
63 views

How to generate a superkey to decrypt strings

I'm working on an application where users have a key or password generated by me that is used to encrypt a string. Each user has their personal key, and no user should be able to decrypt another ...
1
vote
2answers
194 views

Is there man in middle attack when using mobile phone calls?

My question is about the encryption between me and my mobile operator. My mobile operator uses A5/1. I use Samsung. Sometimes I see the symbol G on my phone which means GPRS. I don't know whether it ...
0
votes
1answer
28 views

Can any ECC field element be safely serialized as “compressed” and then restored as uncompressed?

I have a library that stores all its ECC Field Elements in uncompressed form, in a bloated Base64 XML format, and storage has become a concern. (We want to support QR code as a form factor,etc) ...
5
votes
2answers
5k views

Building a web app with encrypted MySQL database entries?

I have some experience in building PHP based websites with MySQL access, storing encrypted user details, but all other fields being plain text. My most recent project will require sensitive data to be ...
1
vote
2answers
103 views

Cryptanalysis of encrypted data at rest

Imagine I have a file encrypted using AES CBC mode with a key and a random IV. The attacker access to the encrypted text and the IV used but not the key. In this scenario there is no vulnerability ...
4
votes
2answers
113 views

Safety of using online proxy?

Lets say for example I have to use a public online proxy like https://www.zend2.com to load a php webpage controlled by me containing sensitive data over https. How would i make sure that the proxy ...
1
vote
7answers
163 views

What are the benefits of encryption for everyday people?

In addition to the fact that encryption systems like PGP are notoriously difficult to use, and that encryption doesn't always jive with cloud-based services like webmail, the fact is that most people ...
0
votes
1answer
37 views

GPG encryption and signing

Why don't the commands gpg2 --armor --sign file.txt and gpg2 --clearsign file.txt have the same output? Also when I use just --sign I get a bunch of binary gibberish surrounding the message in ...
1
vote
1answer
148 views

Making a bitcoin-like secure mail protocol, how to tackle public keys?

I'm making a new mail protocol (probably already exists, but I've learnt a lot of things about security and privacy on the way). Here's the summary(much simpler if you know bitcoin's inner workings): ...
0
votes
1answer
53 views

What Linux software can I use to explore entropy of a file?

I've heard of tools that could be used to graph entropy of a file. Is there a graphical Linux program that I could use for this job that would let me conveniently explore which blocks of a file have ...
0
votes
1answer
33 views

Identifying stream cipher algorithm based on encrypted content

Is it possible to identify the algorithm used for the stream cipher based upon analysis of an encrypted stream?
2
votes
2answers
151 views

Why doesn't Bitlocker mix the password with stored key?

Bitlocker doesn't support USB key + PIN (password). The reasoning was "the password is too weak to provide additional security". Isn't that flawed? With a USB key and password, I've got some level of ...
3
votes
1answer
147 views

Bitlocker lock drive on standby or switch users

Is possible to auto lock drive with bitlocker when the laptop go on standby or sleep mode? Or when the user is changed? I want the drive to be accesible only by one user.
2
votes
3answers
2k views

Why different key exhange techniques for ssl key exchange?

During ssl key exchange, I have read that sending the symmetric key to the server encrypted with the server's public key is an old technique. Now for key echange Diffie hellman and other techniques ...
11
votes
2answers
5k views

Are phone calls on a GSM network encrypted?

When I make a call on my cellphone (on a GSM network), is it encrypted?
4
votes
2answers
393 views

How to implement client side encryption for CalDav & CardDav content?

I'm looking for a client-side encryption implementation that would be able to secure CardDav & CalDav data so that they couldn't be compromised even by the hosting provider. Server side: PHP or ...
0
votes
3answers
98 views

Java AES encryption output length

I am trying to encrypt few database columns (string values) using Java AES algorithm. This is to protect certain sensitive data. For some users these data should decrypted. In Java AES encryption, if ...
-1
votes
1answer
353 views

Why the data in Aircraft's Black Box is Encrypted? [closed]

I have read somewhere that the Data in Air Craft Black Boxes are encrypted using various algorithm and only the manufacturers could gain access to the actual data of the BlackBoxe, Why the data in ...
1
vote
6answers
757 views

Is it theoretically possible to decrypt a file without the key/password?

Hear me out ... On TV shows like Criminal Minds they make it out to appear that any encrypted files can be easily decrypted, even without a key. The character, Garcia, just simply "pushes some ...
176
votes
7answers
125k views

RSA vs. DSA for SSH authentication keys

When generating SSH authentication keys on a Unix/Linux system with ssh-keygen, you're given the choice of creating a RSA or DSA key pair (using -t type). What is the difference between RSA and DSA ...
2
votes
1answer
51 views

Would it be possible to add additional files to a password protected zip 2.0 file

So the scenario is this: I don't have the ability to determine/recover the master password for a production system that uses zip 2 archives. However, I need to be able to add new files to existing ...
0
votes
0answers
9 views

How to store hexencoded ciphertext in Java [migrated]

I am tasked with finding the secret message and I believe that I will have to XOR the different ciphertexts, but I don't understand how to store a ciphertext in a variable in Java. I could not find ...
0
votes
1answer
22 views

In TLS1.2 AES-GCM mode, what happened when input is not exactly the multiple of its block size?

I know that AES-GCM mode does not need padding, and its output are exactly the length of input data plus the tagging. But I am a little bit lost, as AES itself is block cipher, it could only operate ...
15
votes
7answers
5k views

Is TrueCrypt safe enough to store clear-text-passwords?

The reason: I want to be able to use a portable USB drive to access my passwords on any machine and OS. TrueCrypt seems to be the only program that has sufficient support on all major platforms. So I ...