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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Why does my private OpenPGP key look different between devices?

Something I noticed, when I use gpg --export-secret-keys -a on different computers: My private key looks different, even though they are the same key pair. Is that normal or does this indicate ...
18
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3answers
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 ...
3
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2answers
461 views

Storing a user's password in a retrievable manner

I currently store my users passwords as PBKDF2 hashes, for the authentication part of my web application. Each user also has their own private key and public key (also stored in their user profile in ...
6
votes
3answers
99 views

What is the benefit of adding data encrypting key then store it (encrypted) along with data

To protect user's sensitive data, I am considering the following 2 approaches: Create 1 data encrypting key (DEK) for each user, use it to encrypt (using AES CBC mode with a random IV for each ...
0
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2answers
207 views

Why does Telegram not use end-to-end encryption? [closed]

Signal and Telegram are both mobile applications that "try" to ensure secure chats. Signal uses end-to-end encryption, Telegram does this as well (in 'secret chats') but it does not use end-to-end ...
3
votes
1answer
97 views

What happens when encrypted email is in-transit?

If you're using a service that offers end-to-end encryption, what happens when you send an email to another non-encrypted email address? Let's say I write my email in ProtonMail and then send it to a ...
8
votes
3answers
2k views

Why can't the FBI copy the contents of an iPhone they are trying to crack?

Making the news rounds now is a story about the courts ordering Apple to disable the automatic deletion of data after 10 failed password guesses. What I don't understand is, why doesn't the FBI just ...
15
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3answers
10k views

Is email encryption, as claimed by ProtonMail, possible?

Is it possible to create a Web service that encrypts all messages, such that only the writer, and the person to whom the mail is sent, can read it? In other words, is the theory behind ProtonMail ...
2
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6answers
15k 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
votes
2answers
36 views

Could I use a TimeStamp also as IV?

For an academic application, I use AES-GCM to encrypt my frames between 2 parties. To enhance security, and reduce the possibility of replay, I'd like to use a TimeStamp in my frame exchanges. But, ...
13
votes
2answers
636 views

Is there a cipher suite “translator”

I have a list of cipher suites in this format: TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384_P384 Is there a fast, easy way of translating it to more human readable/management readable format? :)
4
votes
3answers
128 views

How to decrypt a file encrypted under multiple public keys GPG

According to https://www.gnupg.org/gph/en/manual/x110.html To decrypt a message the option --decrypt is used. You need the private key to which the message was encrypted. Similar to the ...
10
votes
7answers
6k views

How can I decode a message that was encrypted with a one-time pad?

How can I decrypt a message that was encrypted with a one-time pad? Would I need to get that pad, and then reverse the process? I'm confused here.
3
votes
2answers
399 views

Encryption: Files that can't be encrypted/cryptolocker family doesn't encrypt?

Are there any type of file whatsoever that can -not- be encrypted? Is there any data that can't be encrypted by the regular RSA encryption methods? Also, does anyone know what files the cryptolocker ...
16
votes
3answers
16k views

openssl: recover key and IV by passphrase

A large amount of files were encrypted by openssl enc -aes-256-cbc -pass pass:MYPASSWORD Openssl should derive key+IV from passphrase. I'd like to know key+IV equivalent of that MYPASSWORD. Is ...
3
votes
1answer
80 views

How does ProtonMail manage search?

There is a service called ProtonMail that encrypts email on the client, stores encrypted messages on their server and sends it encrypted in some fashion (depending on what email service the recipient ...
5
votes
1answer
180 views

Which block cipher for a very short (40-bit) message?

Question: I'm trying to encrypt a 32-bit message to produce a ciphertext no longer than 40 bits. Are there vetted block ciphers or other good ways to encrypt very short messages? Are there any ...
2
votes
2answers
55 views

Does Thunderbird Enigmail plugin decrypt attached files?

From my research I have found out that you can easily send encrypted messages to one another using Enigmail. If first I encrypted a file,then attached it to an email, sending it through Enigmail to a ...
-1
votes
1answer
70 views

Tool for reading application data before it's encrypted [closed]

For a test, I have a simple client-server Python socket-based application with a self-signed certificate. The code is copied from here. Although I don't see the traffic as TLS in Wireshark (why?), ...
3
votes
1answer
59 views

uploading pkcs12 to yubikey piv slot

i have a id_rsa (private key which is used by me to authentication and encryption together with cert on yubikey piv smardcart provider on slot 9a) now i wish to use this key to create a pkcs12 ...
2
votes
1answer
94 views

Is storing encrypted and hashed versions of the same data less secure?

I have some database columns which are encrypted. Obviously there is no way to filter these by plaintext value. As the data stored in the db is ~~salted~~ combined with the IV, there is no way to ...
3
votes
2answers
90 views

Is email sent form a Java web-app over a HTTPS connection encrypted?

I'm working on a Java web-application which runs on a HTTPS connection. This application sends emails to its users. I want to protect those emails from man-in-the-middle attacks and other potential ...
64
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5answers
116k views
11
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3answers
1k views

Why can't apple simply add the backdoor now and then remove it after the FBI is done?

Summary of the current situation by @TTT Apple released an open letter to the public outlining their reasons for not complying with the FBI's demands to modify the iPhone's security mechanism. ...
13
votes
5answers
25k views

SHA, RSA and the relation between them

SHA is the hashing mechanism. However, RSA is the encryption algorithm. So does RSA algorithm use SHA hashing mechanism to generate hashing keys which in turn is used to encrypt the message?? ...
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0answers
27 views

Finding the key of encrypted string (given known decrypted message) [duplicate]

I have a bunch of messages where I can run the encrypted message against a validation services, and get a response that the encrypted message is valid as well as the contents of the encrypted message. ...
5
votes
3answers
4k views

How To Recover EFS Cert From Backup?

I made a backup of the old Win 7 Pro then did a clean install. But I forgot to export my EFS encryption certificate, so when after I restored the encrypted files from backup I could no longer access ...
6
votes
2answers
362 views

Am I weakening symmetric OpenPGP encryption by deploying a custom pre-derivation?

I often use GnuPG to encrypt files with a passphrase. I'm very paranoid, and afraid that the key derivation used by GnuPG isn't slow enough. For this reason, I've decided to do my own key derivation ...
3
votes
1answer
50 views

How to prevent data from Interception?

I am a web developer. A few days ago, I used Burp, to intercept facebook's official App over network, by setting up proxy. I noticed that the data was encrypted. While I have been using Json to ...
1
vote
1answer
285 views

Can I decrypt a DiskCryptor-encrypted hard drive using Veracrypt?

I have a hardrive I encrypted with DiskCryptor back when I was using Windows. Now that I have Linux I want to decrypt the hard drive but it turned out DiskCryptor is not available for Linux, whereas ...
3
votes
1answer
6k 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 ...
5
votes
2answers
7k views

Perfectly secure Postfix MTA (SMTP) configuration

I want to secure my root server (further) service by service, starting with the SMTP service (Postfix MTA) as the most busy one. I the course of setting everything up, I read a lot about security and ...
44
votes
5answers
50k 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. ...
3
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2answers
43 views

Specifying my key name while encrypting file to some receiver using GnuPG

I would like to make sure of one thing. When I am encrypting file, the only needed key to specify is --recipient, because I only need to specify key to encrypt (receiver key)? I don't need to specify ...
23
votes
3answers
44k views

Secure Configuration of Ciphers/MACs/Kex available in SSH

Following on the heels of the previously posted question here, Taxonomy of Ciphers/MACs/Kex available in SSH?, I need some help to obtain the following design goals: Disable any 96-bit HMAC ...
35
votes
6answers
3k views

Is C a good choice for security-related software any longer? [closed]

C is a rock-solid and widespread programming language that is very popular especially in the FOSS community. Many security-related software (such as encryption libraries) are written in C and will ...
1
vote
1answer
44 views

Location/proximity based decryption using separate machine

I read a long thread where the whole issue was revolving around deriving decryption keys from GPS location. This has huge issues, as being present at a location is not needed to know the location. ...
4
votes
1answer
215 views

decrypt a string with a password, but unknown method

I want to run through multiple algorithms against an encrypted string. I have the password and the encrypted string but not the method it was encrypted under? what would be the best method to find ...
22
votes
5answers
22k views

Multi-boot with full hard drive encryption and pre-boot authentication

How would I set up a multiboot system which supports full hard drive encryption and pre-boot authentication. I have a system with Ubuntu, Windows 7, Windows XP, and I would like to install Red Hat. ...
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votes
2answers
48 views

How and what is used when information is sent to a hacker's server? [closed]

I'm working in some malware research, my main question is how the victim's data is transfered over the internet, protocol and how? Using HTTP or any other way? As fat as I know the data can be sent ...
1
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0answers
57 views

Encrypted Malicious Traffic Database

I was working on a little research project to correctly identify the encrypted traffic pattern generated by various tools/applications for example metasploit (or increase the success rate). I have ...
5
votes
2answers
150 views

Is AES 128 encryption weak for very small payload size?

If I have a payload of e.g. 8 bits and I want to encrypt it using AES 128, I will need to add some random padding to make the plaintext 128 bits long. Does this padding affect the security of AES?
3
votes
1answer
97 views

Putty settings - Protocols and Algorithms to warn about

I specify "Putty" as otherwise I feel the question would be too broad. What are the algorithm (as of March 2016) that one needs to be warned about (ie, those that no longer are considered safe ...
3
votes
2answers
1k views

IKEv2 vs OpenVPN

I want to ask you for information about the IKEv2 protocol for a VPN connection. I haven't found so much information on the web. I am interested especially regarding the usage on a mobile phone. Is it ...
0
votes
1answer
68 views

Checking a salted hash against known password?

I've created a mysql dump of my users and passwords and awked them into a presentable form: Passwords: ...
3
votes
1answer
163 views

Is it possible to trick a CA into signing a certificate by intercepting on SSL domain validation email?

From my understanding domain validation certificate are verified by receiving an email on some special email addresses on the domain (e.g. postmaster@example.com, admin@example.com) or by sending on ...
1
vote
3answers
124 views

Authenticating user in same sub-domain using cookies

We have few in production websites say site1.dom1.com , site2.dom1.com , site3.dom1.com which are just replicas working on different server. Now we want to extend some application on another server ...
2
votes
1answer
69 views

Cisco Registered Envelope Service (CRES), big security flaw?

While researching so called HIPAA compliant email providers, I came across Cisco Registered Envelope Service(CRES), which claims to be HIPAA compliant. According to this instruction, upon receiving ...
0
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2answers
78 views

Using Two Different Brands of Security Tools To Block Backdoors

There's this idea of using 2 brands of firewalls both inline that is usually brought up: {Internet}<-->FW(A)<-->FW(B)<-->{Internal Network} Or using 2 algorithms: {Plain ...
0
votes
0answers
79 views

How to decrypt a microSD card after a factory reset of the device used to encrypt it?

Two month ago, I encrypted my Micro SD card in my Android device (Samsung Galaxy S5) for security purposes, and yesterday I forgot to decrypt it whilst removing the card I and factory resetting the ...