Do you have information security questions?

I can't recall a time in my life when I didn't have a question, looking for the harbor of satisfaction, floating around in my head. The sad part about my steadfast questions is their inability to tie a good cleat knot causing them to frustratingly drift back into the sea of mystery. The only way I can get them to stay in their slips is to remove them from the waters all together, and the only way I can do that is an overabundance of convincing. I've practically got to beat them into submission with a rod inscribed with the words "How many times do I have to tell you!".

Well, when it comes to my field of concentration, Information Security, that reality is no less true. I needed a repository of information I could reference when needed. Something accesible from anywhere, and under my control. Thank you Tim Berners-Lee for giving me that ability. I guess I should also thank you for opening many more doors of opportunity, for bringing the world closer together, for, let's just be honest here, giving me a career to pursue! Without the World Wide Web cyber security wouldn't even exist. But, I digress. It does exist! And, I am here. And, so are you. So, let's get on to some questions and answers.

Information Security Questions and Answers

  • I want to give credit where credit is due. Not only is it the right thing to do, but I want to. The following questions were taken from the site Infosec Institute authored by Kurt Ellzey. Thank you for sharing your years of experience and knowledge. I have modified some of the answers to fit into my confused, jumbled mess, I call a brain. The rewriting and rewording helps me absorb the information, but the core of the information in this section is credited towards Kurt.

    Most of the answers are written from Kurt's perspective.

1Where do you get your cyber security news?

It seems like we can’t go more than a few days anymore without hearing about a major breach, which on the surface would make it seem that more people and places are being hacked than ever before (which to be honest is true). However, it also shows that detection and reporting of attacks is improving per requirements of both government entities and insurance companies. As a result, the public and security professionals are both better informed as to what they can do to help protect themselves and watch out for falsified charges on their accounts. Keeping up to date on these matters is vital for anyone interested in Information Security.

Here are some great sources:

2How is your home network set up?

Nothing shows you how to break and fix things more than a test environment, and for most people that means their home network. Whether its a Windows laptop with a wireless generic router and a phone all the way up to 14 Linux Workstations, an Active Directory Domain Controller, a dedicated Firewall appliance and a net-attached toaster – as long as you are learning and fiddling with it, that’s what matters.

3What personal achievement are you most proud of?

For me at least, this one is easy- getting my CISSP. I studied for months, did every possible thing I could to improve my recall and asked for anybody and everybody to help ask questions and modify them in ways to make me try to think around corners. Everybody has at least one thing that they are proud of, and while this and the next question may be the same answer, all that matters is showing that you are willing to move forward and willing to be self-motivated.

4What project that you have built are you most proud of?

For some people, this would be the first computer they ever built, or the first time they modified a game console, or the first program they wrote, the list can go on and on. In my case, that would be a project for work that I was working on for years. It started out as an Excel spreadsheet that the Engineering department were using to keep track of their AutoCAD drawings, and ended up evolving through a couple hundred static HTML pages, an Access Database and frontend, and finally to a full on web application running in MySQL and PHP. This simple little thing ended up becoming an entire website with dedicated Engineering, Sales and Quality web apps used by the company globally, which just goes to show you you never know where something might lead.

5How would traceroute help you find out where a breakdown in communication is?

Tracert or traceroute, depending on the operating system, allows you to see exactly what routers you touch as you move along the chain of connections to your final destination. However, if you end up with a problem where you can’t connect or can’t ping your final destination, a tracert can help in that regard as you can tell exactly where the chain of connections stop. With this information, you can contact the correct people – whether it be your own firewall, your ISP, your destination’s ISP or somewhere in the middle.

6Why would you want to use SSH from a Windows pc?

SSH (TCP port 22) is a secure connection used on many different systems and dedicated appliances. Routers, Switches, SFTP servers and unsecure programs being tunnelled through this port all can be used to help harden a connection against eavesdropping. Despite the fact that most times when you hear about somebody ‘SSHing’ into a box it involves Linux, the SSH protocol itself is actually implemented on a wide variety of systems – though not by default on most Windows systems. Programs like PuTTY, Filezilla and others have Windows ports available, which allow Windows users the same ease-of-use connectivity to these devices as do Linux users.

7What’s the difference between Symmetric and Asymmetric encryption?

To boil down an extremely complicated topic into a few short words, Symmetric encryption uses the same key to encrypt and decrypt, while Asymmetric uses different keys for encryption and decryption. Symmetric is usually much faster, but is difficult to implement most times due to the fact that you would have to transfer the key over an unencrypted channel. Therefore many times an Asymmetric connection will be established first, then send creates the Symmetric connection. This leads us into the next topic…

8What is SSL (Secured Socket Layer) and why is it not enough when it comes to encryption?

SSL is identity verification, not hard data encryption. It is designed to be able to prove that the person you are talking to on the other end is who they say they are. SSL and its big brother TLS are both used almost everywhere online, but the problem is because of this it is a huge target and is mainly attacked via its implementation (The Heartbleed bug for example) and its known methodology. As a result, SSL can be stripped in certain circumstances, so additional protections for data-in-transit and data-at-rest are very good ideas.

9How would you find out what a POST code means?

Short for power-on self-test, the POST is a test the computer must complete to verify all hardware is working properly before starting the remainder of the boot process. If the computer passes the POST the computer may return a single beep and if unsuccessful generate a beep code to indicate the error and not boot. POST is one of the best tools available when a system will not boot. Normally through the use of either display LEDs in more modern systems, or traditionally through audio tones, these specific codes can tell you what the system doesn’t like about its current setup. Because of how rare these events can be, unless you are on a tech bench day in and day out, reference materials such as the Motherboard manual and your search engine of choice can be tremendous assets. Just remember to make sure that everything is seated correctly, you have at least the minimum required components to boot, and most importantly that you have all of your connections on the correct pins.

10What is the difference between a Black Hat and a White Hat?

This particular question can lead into a major philosophical debate about freedom of information, and if something is implemented in a deliberately broken way it isn’t actually breaking into it, etc etc. The one I’ve heard the most is the classic Jedi example – same tools, different ideologies. Personally, with the people I know that have worked on both sides of the line it comes down to this – the difference between a Black Hat and a White Hat is who is signing the check.

11You need to reset a password-protected BIOS configuration. What do you do?

While BIOS itself has been superseded by UEFI, most systems still follow the same configuration for how they keep the settings in storage. Since BIOS itself is a pre-boot system, it has its own storage mechanism for its settings and preferences. In the classic scenario, simply popping out the CMOS (complementary metal-oxide-semiconductor) battery will be enough to have the memory storing these settings lose its power supply, and as a result it will lose its settings. Other times, you need to use a jumper or a physical switch on the motherboard. Still other times you need to actually remove the memory itself from the device and reprogram it in order to wipe it out. The simplest way by far however is this: if the BIOS has come from the factory with a default password enabled, try ‘password’.

12What is XSS?

Cross-site scripting, the nightmare of Javascript. Because Javascript can run pages locally on the client system as opposed to running everything on the server side, this can cause headaches for a programmer if variables can be changed directly on the client’s webpage. There are a number of ways to protect against this, the easiest of which is input validation.

How to defend XSS:

13How would you login to Active Directory from a Linux or Mac box?

While it may sound odd, it is possible to access Active Directory from a non-Windows system. Active Directory uses an implementation of the SMB protocol, which can be accessed from a Linux or Mac system by using the Samba program. Depending on the version, this can allow for share access, printing, and even Active Directory membership.

14What are salted hashes?

Salt at its most fundamental level is random data. When a properly protected password system receives a new password, it will create a hashed value for that password, create a new random salt value, and then store that combined value in its database. This helps defend against dictionary attacks and known hash attacks. For example, if a user uses the same password on two different systems, if they used the same hashing algorithm, they could end up with the same hash value. However, if even one of the systems uses salt with its hashes, the values will be different.

15What do you think of social networking sites such as Facebook and LinkedIn?

This is a doozy, and there are an enormous number of opinions for this question. Many think they are the worst thing that ever happened to the world, while others praise their existence. In the realm of security, they can be the source of extreme data leaks if handled in their default configurations. It is possible to lock down permissions on social networking sites, but in some cases this isn’t enough due to the fact that the backend is not sufficiently secured. This also doesn’t help if somebody else’s profile that you have on your list gets compromised. Keeping important data away from these kinds of sites is a top priority, and only connecting with those you trust is also extremely helpful.

16What are the three ways to authenticate a person?

Something they know (password), something they have (token), and something they are (biometrics). Two-factor authentication often times uses a password and token setup, although in some cases this can be a PIN and thumbprint.

17How would you judge if a remote server is running IIS or Apache?

Error messages oftentimes giveaway what the server is running, and many times if the website administrator has not set up custom error pages for every site, it can give it away as simply as just entering a known bad address. Other times, just using telnet can be enough to see how it responds. Never underestimate the amount of information that can be gained by not getting the right answer but by asking the right questions.

18What is data protection in transit vs data protection at rest?

When data is protected while it is just sitting there in its database or on its hard drive- it can be considered at rest. On the other hand, while it is going from server to client it is in-transit. Many servers do one or the other- protected SQL databases, VPN connections, etc, however there are not many that do both primarily because of the extra drain on resources. It is still a good practice to do both however, even if it does take a bit longer.

19You see a user logging in as root to perform basic functions. Is this a problem?

A Linux admin account (root) has many powers that are not permitted for standard users. That being said, it is not always necessary to log all the way off and log back in as root in order to do these tasks. For example, if you have ever used the ‘run as admin’ command in Windows, then you will know the basic concept behind ‘sudo’ or ‘superuser (root) do’ for whatever it is you want it to do. It’s a very simple and elegant method for reducing the amount of time you need to be logged in as a privileged user. The more time a user spends with enhanced permissions, the more likely it is that something is going to go wrong – whether accidentally or intentionally.

20How do you protect your home Wireless Access Point?

This is another opinion question – there are a lot of different ways to protect a Wireless Access Point: using WPA2, not broadcasting the SSID, and using MAC address filtering are the most popular among them. There are many other options, but in a typical home environment, those three are the biggest.

Now I don't agree with Kurt about turning off your SSID. Turning off SSID broadcasting may cause a client to try to connect with every access point in its proximity, which means it will send its authentication data to these APs. If a rogue access point obtains this data, it can facilitate an attack. An attacker will be able to connect to a WPA or WEP network: this means that turning off SSID broadcasting can effectively lower the security of your WLAN

21What is an easy way to configure a network to allow only a single computer to login on a particular jack?

Sticky ports are one of the network admin’s best friends and worst headaches. They allow you to set up your network so that each port on a switch only permits one (or a number that you specify) computer to connect on that port by locking it to a particular MAC address. If any other computer plugs into that port, the port shuts down and you receive a call that they can’t connect anymore. If you were the one that originally ran all the network connections then this isn’t a big issue, and likewise if it is a predictable pattern then it also isn’t an issue. However if you’re working in a hand-me-down network where chaos is the norm then you might end up spending a while toning out exactly what they are connecting to.

22You are remoted in to a headless system in a remote area. You have no physical access to the hardware and you need to perform an OS installation. What do you do?

There are a couple of different ways to do this, but the most likely scenario you will run into is this: What you would want to do is setup a network-based installer capable of network-booting via PXE (if you’ve ever seen this during your system boot and wondering what it was for, tada). Environments that have very large numbers of systems more often than not have the capability of pushing out images via the network. This reduces the amount of hands-on time that is required on each system, and keeps the installs more consistent.

23On a Windows network, why is it easier to break into a local account than an AD (Active Directory) account?

Windows local accounts have a great deal of baggage tied to them, running back a long long way to keep compatibility for user accounts. If you are a user of passwords longer than 13 characters, you may have seen the message referring to this fact. However, Active Directory accounts have a great deal of security tied onto them, not the least of which is that the system actually doing the authenticating is not the one you are usually sitting at when you are a regular user. Breaking into a Windows system if you have physical access is actually not that difficult at all, as there are quite a few dedicated utilities for just such a purpose, however that is beyond the scope of what we’ll be getting into here.

24What is the CIA triangle?

Confidentiality, Integrity, Availability. As close to a ‘code’ for Information Security as it is possible to get, it is the boiled down essence of InfoSec. Confidentiality- keeping data secure. Integrity- keeping data intact. Availability- keeping data accessible.

25What is the difference between an HIDS and a NIDS?

Both acronyms are Intrusion Detection Systems, however the first is a Host Intrusion Detection System whereas the second is a Network Intrusion Detection System. An HIDS runs as a background utility in the same as an anti-virus program for instance, while a Network Intrusion Detection System sniffs packets as they go across the network looking for things that aren’t quite ordinary. Both systems have two basic variants: signature based and anomaly based. Signature based is very much like an anti-virus system, looking for known values of known ‘bad things’, while anomaly looks more for network traffic that doesn’t fit the usual pattern of the network. This requires a bit more time to get a good baseline, but in the long term can be better on the uptake for custom attacks.

26You find out that there is an active problem on your network. You can fix it, but it is out of your jurisdiction. What do you do?

This question is a biggie. The true answer is that you contact the person in charge of that department via email – make sure to keep that for your records – along with CCing your manager as well. There may be a very important reason why a system is configured in a particular way, and locking it out could mean big trouble. Bringing up your concerns to the responsible party is the best way to let them know that you saw a potential problem, are letting them know about it, and covering yourself at the same time by having a timestamp on it.

27You are an employee for a tech department in a non-management position. A high-level executive demands that you break protocol and allow him to use his home laptop at work. What do you do?

You would be amazed how often this happens, even more so in the current BYOD environment. Still, the easiest way out of this one is to contact your manager again and have them give a yay or nay. This puts the authority and decision where it needs to be, and gives you assistance if the department needs to push back. Stress can be a real killer in position where you have to say ‘no’ to people that don’t like hearing it, so passing the buck can be a friend.

28What is the difference between a vulnerability and an exploit?

A lot of people would say that they are the same thing, and in a sense they would be right. However, one is a potential problem while the other is an active problem. Think of it like this: You have a shed with a broken lock where it won’t latch properly. In some areas such as major cities, that would be a major problem that needs to be resolved immediately, while in others like rural areas its more of a nuisance that can be fixed when you get around to it. In both scenarios it would be a vulnerability, while the major cities shed would be an example of an exploit – there are people in the area, actively exploiting a known problem.

29How would you compromise an “Office Workstation” at a hotel?

Considering how infected these typically are, I wouldn’t touch one with a 10ft pole. That being said, a USB keylogger is easy to fit into the back of these systems without much notice while an autorun program would be able to run quickly and quietly leaving behind software to do the dirty work. In essence, it’s open season on exploits in this type of environment.

30What is worse in Firewall Detection, a false negative or a false positive? And why?

Far and away is a false negative. A false positive is annoying, but easily dealt with – calling a legitimate piece of traffic bad. A false negative however is a piece of malicious traffic being let through without incident – definitely bad.

31What’s better, a red team or a blue team?

Another opinion question, more along the lines of where your interests lie. In penetration testing scenarios, a red team is trying to break in while a blue team is defending. Red Teams typically are considered the ‘cooler’ of the two, while the Blue Team is usually the more difficult. The usual rules apply like in any defense game: the Blue Team has to be good every time, while the Red Team only has to be good once. That’s not entirely accurate given the complexities at work in most scenarios, but it’s close enough to explain the idea.

32What’s the difference between a White Box test and a Black Box test?

Information given by the person commissioning the test. A White Box test is one where the pen testing team is given as much information as possible regarding the environment, while a Black Box test is…well…a Black Box. They don’t know what’s inside.

33What is the difference between Information Protection and Information Assurance?

Information Protection is just what it sounds like- protecting information through the use of Encryption, Security software and other methods designed to keep it safe. Information Assurance on the other hand deals more with keeping the data reliable – RAID configurations, backups, non-repudiation techniques, etc.

34How would you lock down a mobile device?

Another opinion question, and as usual a lot of different potential answers. The baseline for these though would be three key elements: An anti-malware application, a remote wipe utility, and full-disk encryption. Almost all modern mobile devices regardless of manufacturer have anti-malware and remote wipe available for them, and very few systems now do not come with full-disk encryption available as an option directly within the OS.

35What is the difference between closed-source and open-source? Which is better?

Yet another opinion question. Closed-source is a typical commercially developed program. You receive an executable file which runs and does its job without the ability to look far under the hood. Open-source however provides the source code to be able to inspect everything it does, as well as be able to make changes yourself and recompile the code. Both have arguments for and against them, most have to do with audits and accountability. Closed-source advocates claim that open-source causes issues because everybody can see exactly how it works and exploit weaknesses in the program. Open-source counter saying that because closed-source programs don’t provide ways to fully check them out, its difficult to find and troubleshoot issues in the programs beyond a certain level.

36What is your opinion on hacktivist groups such as Anonymous?

You might have guessed that this level is very much about forming opinions and drawing conclusions, and you’d be right – this one is an especially loaded question. Like any major group without a central leader, they seem to be mostly chaotic, at times seeming like a force for good, while at others causing havoc for innocents. Choose your words very carefully here, as it could be a dealbreaker.

37What is the Three-way handshake? How can it be used to create a DOS attack?

The three-way handshake is a cornerstone of the TCP suite: SYN, SYN/ACK, ACK. SYN is the outgoing connection request from client to server. SYN/ACK is the acknowledgement of the server back to the client, saying that yes I hear you, let’s open a connection. ACK is the final connection, and allows the two to speak. The problem is that this can be used as a very basic type of Denial of Service Attack. The client opens up the SYN connection, the server responds with the SYN/ACK, but then the client sends another SYN. The server treats this as a new connection request and keeps the previous connection open. As this is repeated over and over many times very quickly, the server quickly becomes saturated with a huge number of connection requests, eventually overloading its ability to connect to legitimate users.

38Why would you bring in an outside contractor to perform a penetration test?

Much like getting a fresh set of eyes on a problem, sometimes you have people that don’t want to see or don’t want to admit to an issue. Bringing in extra help as an audit can really help eliminate problems that your team isn’t able to resolve on their own. Granted they may cost a small fortune, but they are extremely good at what they do.

39If you were going to break into a database-based website, how would you do it?

And here’s other side of the coin: learning to break into your own systems so that you can pen test them yourself. While the exact methods are different for each type of database server and programming language, the easiest attack vector to test for first is an SQL injection technique. For example, if the input fields are not sterilized, just entering a specific set of symbols into a form field may be enough to get back data. Alternatively, depending again on how the site is written, using a specially crafted URL may be enough to get back data as well. Footprinting the server ahead of time can help in this task if it isn’t one you built yourself.

40Why are internal threats oftentimes more successful than external threats?

When you see something day in and day out, even if it shocks you at first, you tend to get used to it. This means that if you see somebody that pokes around day after day, month after month, you might get used to the fact that he’s just curious. You let your guard down, and don’t react as quickly to possible threats. On the other hand, say for example you have an annoyed employee that is soon to be fired and wants to show his soon to be former employer that he can bring them down, so he sells his still active credentials and card-key to a local group that specializes in white-collar crime. Still other infiltrators dress up as delivery people and wander around aimlessly in office buildings, getting information off of post-it notes and papers lying around. External threats do not have access to near this level of information about the company, and more often than not do not get in as far as somebody that spent 20 bucks on a knock-off UPS uniform.

41What is residual risk?

I’m going to let Ed Norton answer this one: “A new car built by my company leaves somewhere traveling at 60 mph. The rear differential locks up. The car crashes and burns with everyone trapped inside. Now, should we initiate a recall? Take the number of vehicles in the field, A, multiply by the probable rate of failure, B, multiply by the average out-of-court settlement, C. A times B times C equals X. If X is less than the cost of a recall, we don’t do one.” Residual Risk is what is left over after you perform everything that is cost-effective to increase security, but to go further than that is a waste of resources. Residual risk is what the company is willing to live with as a gamble in the hopes that it won’t happen.

42Why is deleted data not truly gone when you delete it?

When you press delete on a file, it doesn’t actually go anywhere. A bit on the file is flipped telling the operating system that that file is no longer needed and it can be overwritten as is required. Until that happens, the file can still be restored no matter if it’s in a Recycling Bin or not. There are ways around this, such as using File Shredders and disk wipers, but both of these take quite a bit of time to finish their jobs to a reasonable degree.

43What is the Chain of Custody?

When keeping track of data or equipment for use in legal proceedings, it needs to remain in a pristine state. Therefore, documenting exactly who has had access to what for how long is vital when dealing with this situation. Any compromise in the data can lead to legal issues for the parties involved and can lead to a mistrial or contempt depending on the scenario.

44 How would you permanently remove the threat of data falling into the wrong hands?

If data is on physical media such as a diskette, cd or even paper, there are shredders, pulverizers and destroyers that can turn plastic and paper into confetti. For hard disks however, that becomes a bit more tricky. Most locations will turn to a two-fold method for ensuring a disk’s destruction by first using a specially made disc wiping program, taking apart the hard drive, removing the platters, scratching them up beyond recognition and then degaussing them with a high-powered magnet. This ensures that the data cannot be recovered through conventional means.

45What is Exfiltration?

Infiltration is the method by which you enter or smuggle elements into a location. Exfiltration is just the opposite: getting sensitive information or objects out of a location without being discovered. In an environment with high security, this can be extremely difficult but not impossible. Again we turn to our friends in the fake delivery uniforms wandering around the building, and see that yes there are ways to get in and out without a lot of issues.

46I run an SMB. I have 4 people in my entire company and a web-based store. I don’t have the time, patience or manpower to have a computer guy. Why should I care about exploits and computer jibberish?

This is a classic catch-22 situation: a company doesn’t have enough money to secure their networks, but by the same token they can’t afford a payout if they get compromised. At the same time, they really can’t afford to have a dedicated computer technician, let alone a security consultant. If you are able to explain (in words that don’t make it sound like you’re just fearmongering), an SMB will acknowledge what they need to do to keep their store secure and keep receiving payments since following the money will tend to help move things along.

47I’m the CEO of a Fortune 500 company. I make more in an afternoon than you make in a year. I don’t care about this stupid security stuff, it just costs time and money and slows everything down. Why should I care about this junk?

This one is significantly harder – they are used to having people lie, cheat and steal from them on a regular basis, and when somebody comes in saying that the company is going to lose all this money unless you pay for this, they’re probably going to say no. Therefore, having done your homework and having the support of the local IT team instead of alienating them is vital. Performing site assessments, creating executive summaries and line-by-line breakdowns of what goes where can help them to better understand what is going to be done and keep the project going.

48I’m the legal council for a large corporation. We have requirements to document assets and code changes. We have a very limited budget for this task. How would you resolve this?

This is actually one of the easier ones – you have an informed party, asking for assistance to something that is important. They have money for the project (albeit not much), but it is better than nothing. At the very bottom of the spectrum, this could be accomplished in nothing more than Excel with a lot of time and data entry, moving all the way up the chain to automated Network Scanners documenting everything they find to a database and programs that check-in and out programs with versioning and delta files. It all depends on how big the project is, and how big the company is.

49I’m the new guy – I used to be a coder at my old job and my manager wants me to create some custom programs. I need domain administrator rights for this task. My boss said its alright, and you either give me what I need or you’re fired and he’ll find somebody that will. How do you respond?

Unfortunately you will run into the hardball guy at least once in your career. In this case though, like others we have run into, it’s time to move it up the chain to the manager. They will be able to give the yay or nay depending on exactly what the project is and be able to take the brunt of an attack if it comes.

Healthcare Security Threats

The increase of mobile devices, embedded devices, virtualization software, social media and the consumerization of IT are the top five security threats for healthcare organizations today, says one expert.

Frank Andrus, chief technology officer at Bradford Networks, a security solutions provider based in Concord, N.H., shared with Healthcare IT News what he believes healthcare organizations should consider their top risks – and his recommendations for minimizing them.

Top Five Security Threats in Healthcare

  • So Many Mobile Devices, So Much Risk

    Mobile devices are ubiquitous in today's society, and the number and types of devices used by physicians, nurses, clinicians, specialists, administrators and staff – as well as patients and visitors – is growing at healthcare organizations across the country. Providing anywhere/anytime network access is essential, particularly when instant communication is required to ensure quality patient care. But these devices are launched daily with upgraded versions of operating systems that are ripe for infection.

    Recommendation: Use network access control (NAC) solutions, which offer the ability to identify each type of user and connected device, scan the device for threats – including out-of-date anti-virus or anti-spyware protection – then provide access based on the device and the user's role within the network. The NAC solutions can also provide a view of network security status across all brands of equipment and devices so nothing falls through the cracks. Such a view is crucial in health care organizations, whose networks are often comprised of infrastructure from multiple vendors.
  • Embedded Devices Become the Norm

    As tablets and mobile devices with wide-area network and Wi-Fi capabilities – including medication scanners, patient-monitoring systems and imaging devices – become more common, embedded connectivity makes tracking, monitoring and managing enterprise productivity easier while helping reduce errors. However, embedded connectivity also puts a strain on bandwidth and exposes the network to viruses brought in by a host of new connected devices that are different from traditional PCs.

    Recommendation: Incorporate a security solution that will protect the integrity of critical (and often private) data and close any vulnerability gaps in the network.
  • Virtualization from Desktops to Servers

    Gartner reports that 80 percent of enterprises have a "virtualization" strategy to run more than one application on one server. The strategy is achieved by using virtualization software, which allows servers to run multiple applications with limited investment in hardware and which reduces costs associated with energy, lowering an organization's carbon footprint. The popularity of the strategy is no surprise: Virtualization holds promise for enterprises of all types – including those in health care – looking to significantly reduce hardware and management costs, implement green strategies and make the most of the flexibility offered by virtualized desktops. Unfortunately, as more users move to virtualized environments, more threats arise.

    Recommendation: Healthcare organizations need to remember that hosted virtualized desktops (HVDs) should be viewed in the same way as traditional devices, posing the same – and some new – threats as any connected device. Set the stage now, before adoption explodes, by ensuring that your NAC solution and other network security tools can view an HVD the same way they view a PC.
  • Viruses Spreading through Social Media

    Social media platforms such as Facebook, Twitter and YouTube are here to stay, and even healthcare users are not immune. This means that in spite of a host of malware that can spread like wildfire through social media sites, it may be virtually impossible to permanently block access to social media at your facility.

    Recommendation: Quickly identifying which devices are infected is essential to maintaining network security and protecting crucial data.
  • Becomes Consumer Friendly

    Physicians and employees need access to the facility's network, but the consumerization of IT has made the problem more difficult to manage. As users increasingly adopt their own devices for professional use, health are organizations will see more network security threats. In fact, the consumerization of IT is driving the need for network security solutions that can cover multiple types of devices and infrastructure components.

    Recommendation: A solid NAC system can help stave off each threat. Respond with security solutions that identify any consumer-adopted device, scan for threats and deficiencies, then provision access or automatically remediate problems – regardless of the type of device or location.


Transport Layer Security (TLS) and its predecessor, Secure Sockets Layer (SSL), are cryptographic protocols designed to provide communication security over the Internet. They use X.509 certificates and hence asymmetric cryptography to authenticate the counterparty with whom they are communicating, and to exchange a symmetric key. This session key is then used to encrypt data flowing between the parties. This allows for data/message confidentiality, and message authentication codes for message integrity and as a by-product, message authentication. Several versions of the protocols are in widespread use in applications such as web browsing, electronic mail, Internet faxing, instant messaging, and voice-over-IP (VoIP). An important property in this context is forward secrecy, so the short-term session key cannot be derived from the long-term asymmetric secret key.

As a consequence of choosing X.509 certificates, certificate authorities and a public key infrastructure are necessary to verify the relation between a certificate and its owner, as well as to generate, sign, and administer the validity of certificates. While this can be more beneficial than verifying the identities via a web of trust, the 2013 mass surveillance disclosures made it more widely known that certificate authorities are a weak point from a security standpoint, allowing man-in-the-middle attacks (MITM)

In the Internet Protocol Suite, TLS and SSL encrypt the data of network connections in the application layer. In OSI model equivalences, TLS/SSL is initialized at layer 5 (session layer) and works at layer 6 (the presentation layer). The session layer has a handshake using an asymmetric cipher in order to establish cipher settings and a shared key for that session; then the presentation layer encrypts the rest of the communication using a symmetric cipher and that session key. In both models, TLS and SSL work on behalf of the underlying transport layer, whose segments carry encrypted data.

TLS is an Internet Engineering Task Force (IETF) standards track protocol, first defined in 1999 and last updated in RFC 5246 (August 2008) and RFC 6176 (March 2011). It is based on the earlier SSL specifications (1994, 1995, 1996) developed by Netscape Communications for adding the HTTPS protocol to their Navigator web browser.

The TLS protocol allows client-server applications to communicate across a network in a way designed to prevent eavesdropping and tampering.

Since protocols can operate either with or without TLS (or SSL), it is necessary for the client to indicate to the server the setup of a TLS connection. There are two main ways of achieving this. One option is to use a different port number for TLS connections (for example, port 443 for HTTPS). The other is for the client to request that the server switches the connection to TLS using a protocol-specific mechanism (for example, STARTTLS for mail and news protocols).

Once the client and server have agreed to use TLS, they negotiate a stateful connection by using a handshaking procedure. During this handshake, the client and server agree on various parameters used to establish the connection's security:

  1. The client sends the server the client's SSL version number, cipher settings, session-specific data, and other information that the server needs to communicate with the client using SSL.

  2. The server sends the client the server's SSL version number, cipher settings, session-specific data, and other information that the client needs to communicate with the server over SSL. The server also sends its own certificate, and if the client is requesting a server resource that requires client authentication, the server requests the client's certificate.

  3. The client uses the information sent by the server to authenticate the server, in the case of a web browser connecting to a web server, the browser checks whether the received certificate's subject name actually matches the name of the server being contacted, whether the issuer of the certificate is a trusted certificate authority, whether the certificate has expired, and, ideally, whether the certificate has been revoked. If the server cannot be authenticated, the user is warned of the problem and informed that an encrypted and authenticated connection cannot be established. If the server can be successfully authenticated, the client proceeds to the next step.

  4. Using all data generated in the handshake thus far, the client (with the cooperation of the server, depending on the cipher in use) creates the pre-master secret for the session, encrypts it with the server's public key (obtained from the server's certificate, sent in step 2), and then sends the encrypted pre-master secret to the server.

  5. If the server has requested client authentication (an optional step in the handshake), the client also signs another piece of data that is unique to this handshake and known by both the client and server. In this case, the client sends both the signed data and the client's own certificate to the server along with the encrypted pre-master secret.

  6. If the server has requested client authentication, the server attempts to authenticate the client. If the client cannot be authenticated, the session ends. If the client can be successfully authenticated, or if the server has decided to forego authenticating the client during this session, the server uses its private key to decrypt the pre-master secret, and then performs a series of steps (which the client also performs, starting from the same pre-master secret) to generate the master secret.

  7. Both the client and the server use the master secret to generate the session keys, which are symmetric keys used to encrypt and decrypt information exchanged during the SSL session and to verify its integrity (that is, to detect any changes in the data between the time it was sent and the time it is received over the SSL connection).

  8. The client sends a message to the server informing it that future messages from the client will be encrypted with the session key. It then sends a separate (encrypted) message indicating that the client portion of the handshake is finished.

The SSL handshake is now complete and the session begins. The client and the server use the session keys to encrypt and decrypt the data they send to each other and to validate its integrity.

This is the normal operation condition of the secure channel. At any time, due to internal or external stimulus (either automation or user intervention), either side may renegotiate the connection, in which case the process repeats itself.

This concludes the handshake and begins the secured connection, which is encrypted and decrypted with the key material until the connection closes.

If any one of the above steps fails, the TLS handshake fails, and the connection is not created.

In step 3, the client must check a chain of "signatures" from a "root of trust" built into, or added to, the client. The client must also check that none of these have been revoked; this is not often implemented correctly, but is a requirement of any public-key authentication system. If the particular signer beginning this server's chain is trusted, and all signatures in the chain remain trusted, then the Certificate (thus the server) is trusted.