Note: This class is new in the .NET Framework version 2.0.

Represents the abstract class from which all implementations of Hash-based Message Authentication Code (HMAC) must derive.

HMAC Class (System.Security.Cryptography) for .NET

public class HMac
extends BaseMac

The implementation of the HMAC (Keyed-Hash Message Authentication Code).

HMAC can be used in combination with any iterated cryptographic hash function. HMAC also uses a secret key for calculation and verification of the message authentication values. The main goals behind this construction are

* To use, without modifications, available hash functions. In particular, hash functions that perform well in software, and for which code is freely and widely available.
* To preserve the original performance of the hash function without incurring a significant degradation.
* To use and handle keys in a simple way.
* To have a well understood cryptographic analysis of the strength of the authentication mechanism based on reasonable assumptions on the underlying hash function.
* To allow for easy replaceability of the underlying hash function in case that faster or more secure hash functions are found or required.

HMac (GNU cryptographic primitives and tools, version 2.0.0)

How to: Monitor File System Changes

The following code example uses FileSystemWatcher to register for events corresponding to files being created, changed, deleted, or renamed. Instead of periodically polling a directory for changes to files, you can use the FileSystemWatcher class to fire events when a change is detected.

How to: Monitor File System Changes in .NET

FileSystemWatcher Class

Listens to the file system change notifications and raises events when a directory, or file in a directory, changes.

FileSystemWatcher Class (System.IO) .NET

The use of cryptographic hash functions like MD5 or SHA for message authentication has
become a standard approach in many Internet applications and protocols. Though very easy to
implement, these mechanisms are usually based on ad hoc techniques that lack a sound security
analysis.
We present new constructions of message authentication schemes based on a cryptographic
hash function. Our schemes, NMAC and HMAC, are proven to be secure as long as the un-
derlying hash function has some reasonable cryptographic strengths. Moreover we show, in a
quantitative way, that the schemes retain almost all the security of the underlying hash function.
In addition our schemes are efficient and practical. Their performance is essentially that of the
underlying hash function. Moreover they use the hash function (or its compression function) as
a black box, so that widely available library code or hardware can be used to implement them
in a simple way, and replaceability of the underlying hash function is easily supported.

Keying Hash Functions for Message Authentication

How To: Hash Data with Salt (C#/VB.NET)

The code below demonstrates how to hash data and verify hashes. It supports MD5, SHA-1, SHA-256, SHA-384, and SHA-512 hashing algorithms. To help reduce the risk of dictionary attacks, the code appends random bytes (so-called "salt") to the original plain text before generating hashes. Please keep in mind that salt can only help against prebuilt dictionaries. If an intruder gets access to your system and uses a brute force attack, salt will not provide much value. Code samples are provided in C# and Visual Basic.NET. IMPORTANT: DATA HASHES CANNOT BE "DECRYPTED" BACK TO PLAIN TEXT.

How To: Hash Data with Salt (C#/VB.NET)

A Pint of ALE - Ajax Linking and Embedding

Recently I had to write a document which required the inclusion of some images, a chart, and a few drawings in the text - something that modern word processors allow you to simply and readily do. In fact, the ability to embed and edit rich content directly in a document is actually a pretty handy and powerful feature; arguably one of the more important and enabling features of modern day office suites, such as OpenOffice and Microsoft Office.What is really nice is that the embedded content is saved along with the enclosing document. So for example, if I email a document to a colleague, then the embedded objects I have included into the document follow it to their destination. This embedding capability has traditionally been enabled by leveraging component object models such as Microsoft’s COM/DCOM or IBM’s DSOM and has been the domain of fat desktop applications and office suites.

Zimbra - Blog - A Pint of ALE - Ajax Linking and Embedding

To keep the games interesting, and provide a bit of a educational anomaly, the Red Team had done what any criminal hacker would consider — they broke into the teams’ pods and installed backdoors. Using only the light from a glow stick (the hotel they were staying at didn't have any flashlights), they found a ladder, climbed up the outside of the room (12 foot ceilings), pulled back a drop ceiling tile, and climbed down a wooden rod they collected from nearby. With physical access granted, the Red Team went to town.

A Student-Hacker Showdown at the Collegiate Cyber Defense Competition - Day Three

This is a more detailed flowchart for Georgia civil procedure that I was working on. Would be a good starting point for anyone who intended to work on Hammurabi.

Georgia Civil Procedure Flowchart

An employee of Cognitive Technologies computer company has beaten a man who was selling the company’s software illegally.Manager of the company’s software department, Andrei Smirnov, offered to fight the dealer in a fitness center. He defeated the computer pirate 24-16 in three rounds, lasting three minutes each. The dealer’s name was not revealed, News.Ru web edition on high technologies reported on Thursday.In February, Smirnov saw the dealer selling CDs with his company’s software at a computer market without a license. Smirnov demanded that the dealer stop the illegal sale. A scuffle broke out, but they were stopped by the guard. After that, the pirate expressed a wish to continue the fight in the street, but Smirnov suggested a fitness center.

The Garbuska LIVES!

Russian Software Developer Beats Pirate in Boxing Ring - NEWS - MOSNEWS.COM