Question

his week we will focus on security, and the building blocks.

I would also describe it this way, layers of security. When you build security you want layers, if someone is able to get past one layer you need another and so on.

What examples of security layers can you point out?

Answer 1

Security layers:

layered security is also known as layered defence, describes the practice of combining multiple mitigating security controls to protect resources and data.

Layered security(defence in depth) is one way we can best tackle some of these challenges.

Now a days security has became the something of prime essence not only two organisations but to individuals as well.

But unfortunately the continued in advancement in technology opens more organisations and people who use these Technologies to various risks.

Layered security involves using multiple layers of security controls to protect a system, device or infrastructure.

There are various security controls a few of which are listed below. The use of more than one of these controls constitutes Layered security.

1.Data centric security

2. Encryption

3. Firewalls ( hardware and software)

4. Hashing (passwords)

5. Intrusion detection systems (IDS)

6. Logging and auditing

7. Multi Factor authentication

8. Vulnerability scanners

It is worth nothing that layered security does not necessarily stop the attacker from system exploitation though in some instances it can ( depending on the expertise of the attacker, the system in question, the security control implemented on the system) but its main purpose is to slow down the attacker two give the organisation(victims) time to combat the breach.

In general defence in depth (Layered security ) is a concept of effective security postuer employing multiple tools and Different techniques to slow down an attackers.

For example consider your house, you have a lock on your door dogs fence and CCTV each of these provide a security layer.

For an example

one of the most popular service for remote access that is SSH

layered security implies implementing multiple layer of Defence mechanism to secure a service.

Here is how we can apply Layered security for SSH.

SSH runs at application layer and can be secured at multiple layers in the operating systems.

1. Port knocking : open up the ports on demand. With this technique we can open up the SSH port when REQUIRED.

knocked in Debian and fedora based distros can help you accomplish this. Specifying a Knock sequence of ports we can open and close the ports by instructing ip tables to modify rules on fly.

2. Using TCP wrappers.SSH offers support for TCP wrappers therefore providing one additional layer of security.

3. Using apt configurations for SSH such as using password less COMMUNICATION To the server, running SSH on a different port in contrast to running on the Standard 22 port limiting the SSH access to specific set of users OR GROUPS.