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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9answers
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How can I share files with other individuals using the cloud in a secure way?

I would like to use a dropbox because it is easy and convenient. But I want to encrypt the files with the public key of the intended recipient, so he will be the only one who can access the data in ...
4
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2answers
2k views

openssl_digest vs hash vs hash_hmac? Difference between SALT & HMAC?

openssl_digest vs hash vs hash_hmac I want to use SHA512 for storing password. Which of the above methods are best to use? Why? What is the difference between SALT & HMAC? I just read ...
25
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 ...
5
votes
1answer
105 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?
5
votes
2answers
729 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
votes
1answer
143 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
156 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 ...
14
votes
9answers
9k 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
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3answers
399 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 ...
0
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1answer
48 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 ...
0
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3answers
211 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
72 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 ...
6
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
254 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
10k 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
144 views

Hacking machines using internet packets [closed]

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 ...
3
votes
2answers
146 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 ...
3
votes
1answer
461 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
90 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
33 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
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1answer
59 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
52 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
882 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
72 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
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2answers
206 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
32 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
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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
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2answers
111 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 ...
1
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7answers
180 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
50 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 ...
0
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1answer
69 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
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1answer
39 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?
3
votes
1answer
171 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 ...
-1
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1answer
363 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
970 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 ...
184
votes
7answers
135k 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
67 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
1answer
38 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 ...
1
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1answer
167 views

can I trust Boxcryptor closed source software? Encryption of files for cloud hoster

Boxcryptor https://www.boxcryptor.com is not Open Source. Can I trust this? Is it secure? No government backdoor? Because there is no alternative for OS X and iOS.
0
votes
1answer
90 views

Using ECC like RSA, to Encrypt/Decrypt

Is there any way to implement encryption/decryption using ECC, like RSA does? For example, say some user wants to send a message containing a symmetric key to user X. Then, in RSA, I could just ...
1
vote
0answers
78 views

Traveling abroad with encryption software on my computer [closed]

I have software installed on my computer that has encryption capabilities. This is the case both for things like VPN/SSL, and also GPG. I don't really use GPG (there are not that many people I can use ...
0
votes
0answers
34 views

Sector of small data encryption and transmission

I'm not sure my question is right for this site but still, since its information security so here it goes, I really want to know is there any sector of data encryption that allows or deals with very ...
66
votes
5answers
6k views

How can my employer be a man-in-the-middle when I connect to Gmail? [duplicate]

I'm trying to understand SSL/TLS. What follows are a description of a scenario and a few assumptions which I hope you can confirm or refute. Question How can my employer be a man-in-the-middle when ...
0
votes
2answers
76 views

Are files hosted on cloud servers/websites/databases manually checked by people?

I was wondering ... when I upload a file to, say, Dropbox, does anybody personally check it to see what it is? Say I upload a copy of my Blu-ray movie to cloud storage ... will anyone check, and ...
0
votes
1answer
51 views

What is the strategy used by the itunes store and Google Play to protect and securely install applications on eligible devices?

The requirements for a system like itunes store or google play are as follows; identify and authenticate the user determine if the user has paid for a given app if s/he has, securely transmit the ...
1
vote
1answer
148 views

How to decrypt a file when I have its key?

How could I decrypt a file (encrypted with AES-128) using openssl ? I do not remember the passphrase I used to encrypt it, but I saved the key generated and used to encrypt my file. How could I use ...
2
votes
0answers
41 views

How to identify an encryption algorithm [duplicate]

I have found a small encryption in a programm and would like to identify it, in terms of the public name. I have been programming with a DES and with TEA, but what i have here is not even similar with ...
2
votes
1answer
95 views

Properties of AES Encryption

First of all, I apologize if these questions can be answered using a web search, but I'm sort of a crypto noob and don't know what to search for. Given N AES encrypted messages (where the message ...
1
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2answers
245 views

best place to store backup encryption key [closed]

I have a server on which I keep an encrypted backup of some data. The server updates the backup once a day if the data has been changed and is physically accessible to many people. Further, I would ...