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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24
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5answers
4k views

Why is Bruce Schneier recommending symmetric crypto over public key crypto

I just read the article written by Bruce Schneier, the crypto guru. In the article, he says : Prefer symmetric cryptography over public-key cryptography. But, he doesn't shed any light as to ...
3
votes
1answer
729 views

Securing mobile app rest requests

I am using Facebook login in a mobile native app, and I'm trying to figure out if my approach is secure enough. This is the flow (all communication is made over SSL): User logins to Facebook ...
44
votes
12answers
7k views

Why should I care if a site uses encryption or not if I'm not exchanging any sensitive data? [duplicate]

Lots of sites these days, that don't deal with sensitive data, enable encryption. I think it's mostly to make (paranoid?) users feel safer. In cases where there is a user's account being logged in, ...
11
votes
2answers
5k views

Encrypting with Mongo

How can I achieve the following goals? All compute and storage to be located in the cloud. Encryption in transit of all data between web nodes and db nodes running MongoDB. How to set up tunnels? ...
0
votes
2answers
250 views

What are some examples of a block cipher's versatility over a stream cipher?

I understand that a block cipher can be made to act like a stream cipher at the cost of "losing versatility" of the block cipher for the sake of performance. I don't understand what I'd be losing. ...
-1
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1answer
2k views

Current Encryption Algorithms? [closed]

What are some encryption algorithms that are currently in use by secure websites, by operating systems, or by Secure USB thumb drive manufacturers. I am trying to do research on differences in speed ...
2
votes
1answer
171 views

can you update a one-time pad, over one-time pad encryption (compressed)?

This might well be a silly question, but at the moment I've not thought of a reason it doesn't work. As I think is generally known, you should never re-use a one-time pad. But compression allows you ...
1
vote
0answers
150 views

P2P sharing of uniquely encrypted files

I need a way to share large, uniquely encrypted files (AES256) that are actually the same file when decrypted, through P2P, to optimize download speeds. For instance, a centralized server would ...
3
votes
4answers
691 views

True?: “Nearly all encrypted passwords are stored with the last character in clear text”?

[S]ome passwords are gleaned by hacking into computers where intruders can find stored passwords. Those are stored in encrypted form, but there's software that can attack the encryption. Nearly ...
2
votes
1answer
332 views

Using Encrypt-then-MAC in SSL

SSL typically makes use of MAC-then-Encrypt technique instead of Encrypt-then-MAC (which is usually considered ideal for most of the scenarios). I myself don't have a full insight knowledge about the ...
1
vote
1answer
179 views

Need help designing an encryption workflow

Background: I'm building a .NET application, a very small part of this application allows for users to communicate with a third party application. I am designing this aspect. The third party simply ...
1
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2answers
1k views

SSL/TLS : Authentication mechanism

I have these doubts regarding authentication in SSL/TLS : Will there be an authentication involved for all SSL connections ? For eg. when I browse the internet, using the most up-to-date browser, ...
5
votes
2answers
2k views

How to encrypt more than 16 bytes using AES?

I am trying to implement AES on an image of size 256x256 (65536 bytes) but AES works on 4x4 size of image (16 bytes). What should I do? Can it be implemented or not? And if yes, then how?
2
votes
4answers
470 views

Can I use elliptic curve DSA in a secure message service?

I'm looking to design a system that allows a user of a crypto-coin such as Bitcoin to both have an online wallet and to be able to send and receive encrypted emails in the same system. The relevant ...
20
votes
5answers
9k views

Why should one not use SSL? [duplicate]

I see a lot of posts all over the web asking whether or not they should be using SSL to secure their website, or if it's really necessary to do so when the content of their site does not contain or ...
1
vote
0answers
61 views

Is it possible to produce incorrect Metadata?

There is an app on xposed installer called XPrivacy for android that let's you decide what information you want your device to give a specific app and for information you don't want to give it ...
0
votes
1answer
282 views

What kind of encoding/hash it is [closed]

I have email which is stored in Cookie : %2FGl%F8%7E%06%F1S%FEF%10%E0T%B3%95%82BK%D9%D3%94%BC%AE%E1 which is sth like this after convert it with this tool : ...
7
votes
2answers
3k views

SSL Session resumption and IDs

Some sites, as seen in the report for www.mbank.com.pl [ssllabs.com] or report for aliorbank.pl [ssllabs.com] do not support "Session resumption", either because IDs are assigned but not accepted ...
1
vote
1answer
627 views

Which approach to encrypting data on a per-user basis is more secure?

As a bit of a thought experiment, I've been thinking through how one might design a web application where a user's data (say, from a form on a webpage) is stored, encrypted, on the server, using a ...
1
vote
2answers
234 views

How secure is my system?

I am creating an application that allows a user to create an account, with a password, and have a set of public and private keys symmetrically encrypted with the password, so that they can be ...
5
votes
3answers
4k views

What are the odds of brute-forcing an archive with 256-bit encryption?

I have a file (a stand-alone archive). I lost the password to it, but it has been encrypted using 256-bit encryption. The password is some 20-odd characters long (including non-alphanumeric ...
1
vote
1answer
349 views

My WCF application uses 2 way certificate message encryption - does it still need SSL?

I have a WCF service configured to use two-way certificate authentication on the messages. The server is also locked down through a firewall to only allow traffic from a single IP:Port that the ...
2
votes
2answers
533 views

How to maintain security and trust with a PGP keypair for a team or group of people?

I've seen many instances where a company or organization generates and uses a PGP keypair for a team or group of people. Most likely they all have a copy of the private and public keys on their ...
2
votes
2answers
528 views

If I change my private key PGP passphrase, will the old private key+old passphrase work to decrypt already encrypted data?

Suppose I have a script that contains my PGP private key in plain text and requires me to manually type in the key passphrase to decrypt some data. Later, I decide that my passphrase is compromised ...
2
votes
1answer
579 views

Is there a widely used protocol which builds on AES/GCM, and defines serialization formats of A, IV, C and T together?

note: Title edited to make the answer more useful to a wider audience I'm reading source code for encrypting files with AES GCM and see the following binary output. AdditionalAuthData IV ...
0
votes
1answer
52 views

Generate Passphrase from the data & encrypted data

right now I'm thinking about how to secure some data inside an Application... Now i have the following problem: Is it possible to generate the passpharase from a decrypted message and the same ...
-11
votes
3answers
622 views

Would this kind of encryption be good at anything?

I have put much thought into this very simple algorithm and I have no clue if it was thought before... But I think it should have. I also know nothing about other encryption algorithms so I can't tell ...
4
votes
3answers
7k views

How secure is ionCube compiled code?

I use ionCube to keep the code I write concealed for my customers. If I would store a password inside the code and compile (not encrypt) it with ionCube encoder, would it be possible for a potential ...
0
votes
1answer
234 views

Review of approach to client-side only hashing and encryption for web application

Background: I have little knowledge of hashing and encryption, so please bear with me. I have posted a related question here: ...
5
votes
5answers
780 views

HOWTO : Email encryption in a browser

I have read about encryption and I think it's a good idea for me to encrypt my email. I run ubuntu 12.10 and use Firefox for browsing. In my quest for learning how to use gmail/hotmail to send and ...
0
votes
1answer
313 views

How do I identify a DES encryption key in a dump file using winhex?

I've created a C# program that encrypts and decrypts a file. The encryption method is DES. The program is exactly the same as in the following link, except that the part that removes the key from ...
0
votes
2answers
425 views

Best practice for sending IP Addresses

IP Addresses are pretty common around the internet so they're often easily found in plain text. However, let's say there's a number of IP addresses configured on a server to allow access through a ...
2
votes
1answer
1k views

Which mail clients support PGP/MIME - is there an overview? [closed]

Does anyone know if there is a current overview (I only found ones from before 2006) which MUAs (mail clients) do support PGP/MIME? I wonder whether there still exist issues like "Outlook Express ...
0
votes
1answer
393 views

Can I rely on encrypted cloud services like Mega? [closed]

The Mega site claims that all submitted files are encrypted upon upload and decrypted upon download, and at no moment have they any knowledge of the decrypted contents. (I assume others sites do it ...
1
vote
1answer
141 views

Data Protection act, who is liable? [closed]

Recently, a large UK shopping chain had the staff payroll database leaked (including bank details, all unencrypted) We've been told that we cannot take legal action and have so far been denied ...
0
votes
2answers
171 views

If P=NP, what is still cryptographically secure? [duplicate]

I know, I know - "If P=NP" is a really large, high-impact assumption. But this is a hypothetical. I mean, clearly RSA (and similar methods of obfuscation) would likely become totally irrelevant - or ...
4
votes
5answers
2k views

Can the wifi administrator in a shared office see mail sent through outlook?

I am hot desking in the same office as a potential competitor & would be using the same wifi. The building owner runs the competitor company. My question is, can the wifi administrator see mail I ...
1
vote
0answers
390 views

Bouncy Castle C# API and NTRUEncrypt

I want to play around with NTRUEncrypt and I found this tweet that NTRUE is now part of bouncy castle. But I cannot find any proof of the existence in the source code of teh Bouncy Castle C# API, ...
2
votes
2answers
6k views

Is Salt, IV and Key necessary when encrypting password in a database using AES? If so, how should they be used?

Imagine I have a website with user accounts. I want to authenticate users, so I need to know if the password they provide matches the one stored in my database. To protect the passwords from prying ...
5
votes
1answer
630 views

GnuPG/KGpg Sign PGP Key - Sign User ID : What is the difference?

What is the difference between signing a user ID and a whole Key ? Which behavior is the best as to signing user IDs and Keys ? How and when to use "Local signatures" (non exportable) ? (I was told ...
14
votes
8answers
5k views

Is Steganography a safe method to store secret data?

I want to put some parts of my secret data into specific file with Steganography method. Is this method as safe as other encryption methods like RSA or SHA?
1
vote
2answers
720 views

Google's usage of RC4

I was reading about Google's usage of RC4 and an answer on stackexchange website stated the following: I know Google uses RC4 for most of its services, and this is the reason one shouldn't keep ...
1
vote
2answers
722 views

Using EncFS on a USB drive

I am using EncFS with a USB drive. How secure is this if my USB drive gets stolen? I ask because the .encfs6.xml file is saved in the USB drive and I can open it with a normal text editor. Do I ...
-1
votes
1answer
2k views

MCRYPT_RIJNDAEL_256 max key allow? [closed]

maximun key for MCRYPT_RIJNDAEL_256 ? mcrypt_encrypt( MCRYPT_RIJNDAEL_256, <<==hash_hmac using sha512==>>, $text, MCRYPT_MODE_ECB, $iv ) Warning: mcrypt_encrypt(): Size of key is too large for ...
0
votes
1answer
157 views

What would be a valid approach to store private keys?

I'm implementing a mobile app which uses AES encryption algorithm to encrypt some critical values being sent to a remote server (basically, the user password), and then decrypted on the server side ...
16
votes
3answers
1k views

Storing passwords in reversible form - a genuine use-case

What's wrong with you, you crazy fool, you're not supposed to be able to retrieve a password in plain text! I know. Hear me out. Assume I've got a service that's similar to Mint.com. For those that ...
-1
votes
1answer
420 views

How do I find out what kind of encryption this is and how to decode it? [closed]

0xugm5chUcCO+KqKV58YwSwh3kMOHDFju8wtSIuZCbBAAFJaHkYDloRXz9qLEz3unGiAwZEyTvlRhnt6slOFZQ== Im wondering how to figure what this is and how to decrypt it.
4
votes
1answer
226 views

Why is it bad encrypt to with plain passwords as encryption key?

It's my understanding that using "normal" passwords, such as an easy to remember sentence, is bad practice. Is that because such a string will not be random enough, or something else? From Ruby's ...
3
votes
2answers
242 views

How does my bank knows my second and forth chars of my password [duplicate]

I see that the new login mechanism used by some banks in UK and also used by visa debit authentication is to ask for three random characters from your password at login (for example second, ninth and ...
0
votes
1answer
153 views