Security

A blacklist usually refers to a list of email or IP addresses known to send spam emails or some other type of unsolicited messages. Such lists are currently used by mail servers for filtering incoming emails and blocking the ones listed, in order to improve mail security and integrity. The blacklist is also the opposite of what is called a whitelist.

This guide describes how to generate and use a private/public key pair to log in to a remote system with SSH using PuTTY. PuTTY is an SSH client that is available for Windows and Linux (although it is more common on Windows systems). Using key-based SSH logins, you can disable the normal username/password login procedure which means that only people with a valid private/public key pair can log in. That way, there is no way for brute-force attacks to be successful, so your system is more secure.

DomainKeys is an anti-spam software application in development at Yahoo that uses a form of public key cryptography to authenticate the sender's domain. dkfilter is an SMTP-proxy designed for Postfix. It implements DomainKeys message signing and verification. It comprises two separate filters, an outbound filter for signing outgoing email on port 587, and an inbound filter for verifying signatures of incoming email on port 25. This document shows step-by-step how to install dkfilter for Postfix to deploy DomainKeys signing and verification.

ASSP stands for Anti-Spam SMTP Proxy. The ASSP server project is an Open Source platform-independent transparent SMTP proxy server that leverages numerous methodologies and technologies to both rigidly and adaptively identify spam. In short ASSP is the most kickass solution that is both free and works great. It reduced spam to an absolute minimum for me.

How-to configure Snort with SnortSam to be a real time Instrusion Prevention System

Article on how to create a chroot environment using mod_security. Also has great tips for hardening PHP and MySQL configuration at the server level.

How to protect yourself from identity theft. A good resource to educate yourself and avoid being a victim.