Tagged Questions

8
votes
3answers
141 views

Is it preferable to perform encryption using database functions or code?

Several databases I am familiar with provide functions or modules for encryption. Examples include dbms_crypto for oracle databases and built-in functions for MySQL. Most of the commonly used ...
4
votes
2answers
311 views

Could the bcrypt-ruby binding be vulnerable?

While developing a Ruby on Rails application using a commonly used authentication library named devise, I noticed from the prefix $2a$ of the produced password hashes in the application database that ...
5
votes
2answers
575 views

Keeping user data private in a cloud environment like Google App Engine

I am writing an open-source Java application for Google App Engine (GAE). The application will let users create content that is intended to be private. I want to provide reasonable assurances that ...
3
votes
1answer
382 views

Securing sensitive data in a DB,is using H2 worth it?

I am designing a web application at the moment, and one of the requirements is to secure the user credentials as well as their roles. Now ofc besides the usual pwd hashing + salt +.... I was thinking ...
7
votes
8answers
570 views

Is the following authentication scheme secure?

I was trying to design an authentication system that would make it much harder to guess a password via brute force, and reduce the risk to a user if the hashed password was stolen through a snooping ...
2
votes
3answers
784 views

AES for key encryption

Is AES a good choice for protecting a key stored on the computer of a user of my application? I have seen threads on hashing passwords that suggest using slow algorithms for defending against brute ...
5
votes
4answers
690 views

Using password hash as session ID?

For a rich client web app, on the server I need to verify that each call comes from a legally logged in user. Obviously user ID is not enough, because that's easy to guess. I have an idea I am ...
14
votes
4answers
749 views

What to transfer? Password or its hash?

Let's say in my database I store passwords hashed with salt with a fairly expensive hash (scrypt, 1000 rounds of SHA2, whatever). Upon login, what should I transfer over the network and why? Password ...
12
votes
3answers
1k views

When using AES and CBC, can the IV be a hash of the plaintext?

[Originally on programmers.stackexchange.com with title: Can you encrypt with AES+CBC and search the encrypted data] Basically, I'm going to go with Advanced Encryption Standard with either ...
35
votes
4answers
5k views

Recommended # of iterations when using PKBDF2-SHA256?

I'm curious if anyone has any advice or points of reference when it comes to determining how many iterations is 'good enough' when using PBKDF2 (specifically with SHA-256). Certainly, 'good enough' is ...
8
votes
3answers
25k views

How can I export my private key from a Java Keytool keystore?

I would like to export my private key from a Java Keytool keystore, so I can use it with openssl. How can I do that?
5
votes
4answers
295 views

What is the solution to Schneier's Law?

Schneier's law (which should probably be called Babbage's Law). States that: Anyone, from the most clueless amateur to the best cryptographer, can create an algorithm that he himself can't ...
5
votes
5answers
891 views

Should one sign and encrypt using the same key? The Azure Training Labs are taking this approach

I'm taking the Azure lab LoadBalancing with WCF and recognise what I have been told is bad from a security perspective, but am not sure if it applies here. Can someone look at this code and tell me ...
5
votes
2answers
589 views

Generating one-time tokens from API-key?

I have a web-site for which I'm building a Drupal module that allows the users of that Drupal site to navigate to my web-site directly from the Drupal site. I intend to distribute secret API-keys to ...
3
votes
1answer
153 views

When does one need to be concerned with leaking timing information in .NET?

According to this post, Dominick Baier was comparing two HMACSHA256 signatures and was leaking timing information upon an unsuccessful comparison. When working with .NET crypto classes, when should ...
6
votes
1answer
2k views

How can I enumerate all the saved RSA keys in the Microsoft CSP?

I have an application that is creating several keys and storing them in various stores (in this case the Machine store). How can I enumerate all the keys on a given Windows system? ...
4
votes
1answer
507 views

Why does Bouncy Castle have a separate download for the IDEA algorithm?

I'm looking at downloading the C# binary for Bouncy Castle and see two downloads with source code. One has the IDEA algorithm, the others presumably not. http://www.bouncycastle.org/csharp/ Why ...
3
votes
1answer
2k views

How do I use C# to encrypt/decrypt data where the private key is on a smartcard, hardware security module, TPM chip etc

Is anyone aware of a C# code sample to interact with smartcard, hardware security module, TPM chips (etc), that will allow me to encrypt and decrypt data? My goal is to allow my application to ...
114
votes
11answers
14k views

How to securely hash passwords?

If I hash passwords before storing them in my database, is that sufficient to prevent them being recovered by anyone? I should point out that this relates only to retrieval directly from the ...