Questions tagged [encryption]

For questions about encryption and decryption of data, which is the process of encoding data in such a way that adversaries cannot read or tamper with it. Technical questions about encryption (e.g. how does algorithm X work?) are off-topic but might be in scope for our sister sites about Information Security and/or Cryptography.

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79
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15answers
28k views

Why should passwords be encrypted if they are being stored in a secure database?

I have a web service. Right now, I have passwords stored in plain text in a MySQL table on my server. I know this isn't the best practice, and that is why I am working on it. Why should passwords be ...
45
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13answers
11k views

Encrypted content in games

I have been having this idea of using encryption to prevent users from figuring out content in my program outside of the program itself. Like users may find textures never used in the game meant to be ...
29
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7answers
4k views

Is there any algorithm pattern to protect any content in the web to ensure I am the first one who created it?

A few years ago there was this hacker (don't remember who he was) that full disclosed a vulnerability in a given system, but to make sure nobody took credit for that, he created some kind of PGP key. ...
28
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4answers
1k views

Zero-knowledge code hosting? [closed]

In light of recent revelations about widespread government monitoring of data stored by online service providers, zero-knowledge services are all the rage now. A zero-knowledge service is one where ...
23
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4answers
4k views

Is this simple XOR encrypted communication absolutely secure?

Say Alice and Peter each have a 4GB USB flash memory stick. They meet and save on both sticks two files named alice_to_peter.key (2GB) and peter_to_alice.key (2GB) which contain randomly generated ...
21
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4answers
5k views

Programmers' concerns about export restrictions from the United States

Which aspects do I need to consider when designing and publishing software that must meet the US export restrictions for cryptographic software? Wikipedia says that there are various categories which ...
16
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7answers
18k views

Should I encrypt data in database?

I have a client, for which I'm going to do an Web application about patient care, managing patients, consults, history, calendars, everything about that basically. The problem is that this is ...
15
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6answers
1k views

How to assure users that website and passwords are secure [closed]

On reliable websites I always see claims such as "All data is encrypted" or "All passwords are encrypted using 128bit encryption" and etc. However I have never come across a claim such as "All ...
13
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2answers
2k views

How can I get my own encryption algorithm tested?

I've just developed a block cipher symmetric-key algorithm and I am using it in some of my products. I want to put it to real test. How would one go about entering their encryption algorithm into an ...
13
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3answers
2k views

Where do you use ROT13?

I was reading through the docs for vim, and noticed there's a shortcut, for example g?w would transform the next word using ROT13. I also know that you can change the encoding of a Python file to ...
12
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2answers
241 views

Saving critical data in (third party) databases

How do you save important(privacy-wise) user data like SSN, Credit Card Numbers and Addresses in databases? Scenario: Only data which needs to be available is saved. For eg, SSN is saved because the ...
9
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2answers
1k views

Encryption Cannot Be Reversed?

I am under the impression that an encrypted string cannot be decrypted so the original value is lost forever. However, if the following string always equals "dominic" (my name), then can't there be ...
8
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3answers
8k views

How does a web browser save passwords?

How do current web browsers (or mobile mail clients and any software in general) save user passwords? All answers about storing passwords say we should store only hashes, not the password themselves. ...
8
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2answers
329 views

Data encryption/protection - where to find info about high-level best practices [closed]

I feel that no one in the group I work in, myself included, really groks encryption and security, or the reasons behind making certain decisions. For example, we recently had a conversation regarding ...
7
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3answers
701 views

Cross border data obfuscation and how to deal with it?

I am currently facing a situation where I will need to obfuscate data for legal reasons (these are countrywide rules and not specific to me) I will still need to work with teams outside this area who ...
6
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3answers
15k views

How do I encrypt the source code on the webserver?

I have a web application developed using Python, HTML, CSS & JavaScript. The customer installs it in any of their own Machine and uses it through their LAN. In short the customer sets up the ...
6
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4answers
744 views

Public-key cryptography security given NSA resources

I was wondering how secure public private key encryption methods are. If two individuals were sending emails back and forth forever, where each person would encrypt the body of the email they were ...
6
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2answers
847 views

Licensing issue for RSA and Rijndael algorithms

I'm using .Net to build a commercial application, i.e. a secure chat application. This application is using RSA and Rijndael algorithms. Do we need licenses for using RSA and Rijndael algorithms for ...
6
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2answers
5k views

Easy Licensing enforcement techniques for C++ Program in Windows

I am developing software in Window 10 and Visual Studio in C++. I would like to restrict the use of the software to a set of computers, by implementing a license control. My thought is to query a ...
6
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2answers
4k views

I need advice developing a sensitive data transfer/storage/encryption system

I got closed on SO and told to post this here as it's about general application design as opposed to specific code. Intro I'm currently working on a project which involves the daily extraction of ...
6
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3answers
10k views

How to implement simple secure client side encryption

I know these sorts of questions come up, but I couldn't find a simple answer, most of the answers are "don't do that" For play, I built myself a webapp, it uses sjcl to encrypt and decrypt notes on ...
6
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1answer
6k views

Are PGP keys as good for certificates as X.509 keys?

I'm working on a decentralized transaction processing system that needs both authentication and general encryption, and I have a design decision to make: should I use PGP or X.509 certificates? While ...
6
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2answers
1k views

Client side authentication through signatures instead of passwords

I want to save some user-generated data with some signature of the user that generated it (let's say that the user has to fill some forms with some data and I want him to sign the written data). The ...
5
votes
5answers
19k 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 ...
5
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2answers
2k views

Encrypting stored data for multiple unique users to access information

Developing a database for many users, and thousands more "people" in the database, one section requires we encrypt the personal data - Youth's information, medical information, etc. We have users who ...
5
votes
4answers
748 views

Multiuser System With Encrypted Database

I am currently developing a hosted solution in ASP.NET using MVC3 and Entity Framework. This product will then be made available to a number of clients as a hosted solution. As the data stored by ...
5
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2answers
5k views

do I need French export compliance approval to submit an iOS app that uses encryption? [closed]

My company just (5th July 2011) received the following email from Apple: Starting in the first week of July, apps that meet the following criteria are required to comply with French ...
5
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4answers
305 views

Copyright issues with encryption algorythms

I'm developing an application for Android/Java. This application is a kind of password manager, so I'm storing encrypted passwords under the hood of a master password. There are a number of encryption ...
5
votes
2answers
144 views

Is it possible to validate code execution from a remote server?

I'm looking for a way to achieve some kind of code execution validation, so for example if I have a server and a client, I want the client to execute some code (assembly) and send the server ...
5
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2answers
1k views

Is a PHP file secure enough on a GoDaddy Server to hard code an AES salt into the file?

So I am creating a web api for an app I am making. The data is sanitized before it is sent to my web api and then encrypted before it is stored in my MySql server. The phone app sanitizes then ...
4
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5answers
1k views

Paranoid Encryption

Call me paranoid, but I really like to keep my stuff secret, but readily available on the cloud. So, asking this question. How safe and reliable is encryption software (e.g., truecrypt)? The reason I ...
4
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4answers
2k views

Should I perform encryption in the front end or within the database?

I want to store an encrypted string (specifically, email addresses) in a database. I'm currently using Python and MySQL. I was initially going to use MySQL's AES_ENCRYPT/DECRYPT to handle it, but then ...
4
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3answers
1k views

Saving Passwords for autologin

I know I should encrypt the password whenever I save passwords for security. But I don't know how should I encrypt password that when I save for autologin. If the password was just for checking user,...
4
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3answers
4k views

Options for client-side encryption of local web databases

My scenario is as follows: Web application, run from the browser, designed for mobile devices. Uses WebSQL storage which may contain sensitive data. Uses Application Cache to enable offline use where ...
4
votes
3answers
515 views

Login into application at startup

Short version: I want "Login on program startup" checkbox like in Skype, for example, but don't know how to protect saved credentials securely. I'm writing client application which, before doing ...
4
votes
1answer
327 views

How can social security numbers be safely stored in databases and retrieved?

How can personal information that needs to be retrieved at a later date be stored securely in a database? For instance when companies store social security numbers and use them for taxation purposes. ...
4
votes
1answer
1k views

Decrypt data on any Windows computer by same user

I have a license system which currently locks licenses to a physical computer using CryptProtectData (with CRYPTPROTECT_LOCAL_MACHINE) and CryptUnprotectData. This is of course not the entire license ...
4
votes
3answers
3k views

URL Encryption vs. Encoding

At the moment non/semi sensitive information is sent from one page to another via GET on our web application. Such as user ID or page number requested etc. Sometimes slightly more sensitive ...
4
votes
2answers
152 views

How to add users to a mapping table?

In the accepted answer to "Encrypting stored data for multiple unique users to access information", @lserni describes a mapping table for users. But among the operations for the table, they didn't ...
4
votes
2answers
1k views

Store encrypted data in XML

Context I work in the energy domain with devices that send data in clear text over some medium, that finally ends on a computer. The data is there decoded and stored in XML files. A current XML file ...
4
votes
5answers
880 views

Whats safest way to tell if decryption was successful?

I'm making a C program that uses GTK3 (best documentation ever) and OpenSSL (worst documentation ever) to simply encrypt/decrypt a file using a password. The encryption and decryption functions are ...
3
votes
4answers
1k views

Security through obscurity and storing unencrypted passwords

What exactly does "Security through obscurity" means in the context of stroing unencrypted passwords? I'm using a small program (I won't name it, to not enlarge enough large shame on its author) that ...
3
votes
3answers
397 views

How would I go about changing encryption methods on existing passwords?

If I have an application that is using a less secure method for storing passwords, such as SHA-1, how would I go about converting to SHA-256 or SHA-512?
3
votes
4answers
133 views

How to restrict viral file sharing

So I have a website I would like to make that would essentially be selling files. For the sake of discussion let's say that these files are like the raw text of a book. If somebody buys a file from my ...
3
votes
5answers
1k views

Should I encrypt mobile number and otp when sending to backend

I have a login page, where user logs in via his mobile number, He gets an OTP send via backend server, once he enters a One-Time Passcode (OTP), we hit an API like this: https://backend.com/api/login?...
3
votes
2answers
13k views

HTML5 localStorage and encrypted sensitive data

I'm looking for a way to have a website remember sensitive data, but without actually storing it server side. And I was looking at HTML5 localStorage to do it. Here's the plan as I see it. User ...
3
votes
2answers
425 views

What encryption method should I use?

I am looking for some information on encryption. Here's what I'm trying to do: Get unique information from our customer (an ID or something) Generate and encrypt some data on our side (using the ...
3
votes
3answers
946 views

Do you know of any encryption techniques used to validate url redirection

I'm adding a click-tracking feature on my website to track click-thrus for my advertisers. So, on my site, instead of having a direct link, I link to my re-direct page passing the destination url as ...
3
votes
1answer
906 views

Strategy for Public / Private API, Encrypted (or Hashed) Data, and Server Compromise

In this very simplistic but realistic scenario, I have 2 combo web/database servers (A) behind a load balancer and a single IP address. They also permit access only from one IP address -- the client (...
3
votes
2answers
1k views

How to handle encryption key conflicts when synchronizing data?

Assume that there is data that gets synchronized between several devices. The data is protected with a symmetric encryption algorithm and a key. The key is stored on each device and encrypted with a ...