TPM: The heavy artillery of cryptography

Data security is becoming a virtual battleground — evident by the number of major data breaches that have broken out at retailers such as Target, Staples, Dairy Queen, Home Depot and EBay, at major banks such as JP Morgan, and at many other institutions worldwide. The recent spate of security viruses such as Heartbleed, Shellshock, Poodle, and BadUSB (and who knows what’s next) have been creating serious angst and concern. And, rightfully so. The question is what exactly should you bring to the cyber battleground to protect your assets? This question matters because everyone who is using software to store cryptographic keys is vulnerable to losing sensitive personal data, and today that is just about everybody. So, choose your weapons carefully.

Fortunately, there are weapons now available that are very powerful while still being cost-effective. The strongest data protection available comes from hardware key storage, which beats software key storage every time. Keys are what make cryptography possible, and keeping secret keys secret is the secret to cryptography. Atmel’s portfolio contains a range of innovative and robust hardware-based security products, with the heavy artillery being the Trusted Platform Module (TPM).

TPM

The TPM is a cryptographic device with heavy cryptographic firepower, such as Platform Configuration Registers, protected user configurable non-volatile storage, an enforced key hierarchy, and the ability to both seal and bind data to a TPM. It doesn’t stop there. Atmel’s TPM has a variety of Federal Information Processing Standards (FIPS) 140-2 certified cryptographic algorithms (such as RSA, SHA1, AES, RNG, and HMAC) and various sophisticated physical security counter-measures. The TPM can be used right out-of-the-box with standards-based commands defined by the Trusted Computing Group, along with a set of Atmel-specific commands, which are tested and ready to counter real world attacks.

The Arsenal

Platform Configuration Registers and Secure Boot

One of the important weapons contained in the TPM is a bank of Platform Configuration Registers (PCRs), which use cryptographic hashing functions. These registers can be used to ensure that only trusted code gets loaded at boot time of the system. This is done by using the existing data in a PCR as one input to a hashing function with the other input being new data. The result of that hashing function becomes the new PCR value that will be used as the input to the next hashing function with the next round of new data. This process provides security by continuously changing the value of the PCR.

As the PCR value gets updated, the updated values can then be compared with known hash values stored in the system. If the reference values previously stored in the TPM compare correctly with the newly generated PCR values, then the inputs to the hashing function (new data in the diagram) are proven to have been exactly the same as the reference inputs whose hash is stored on the TPM. Such matching of the hash values verifies the inputs as being authentic.

The PCR flow just described is very useful when enforcing secure boot of the system. Unless the hashes match showing that the code is, indeed, what it is supposed to be, the code will not be loaded. Even if a byte is added, deleted, changed, or if a bit is modified, the system will not boot. For secure boot, the data input to the hashing function is a piece of the BIOS (or operating system).

User Configurable Non-Volatile Storage

Another weapon is user-configurable, non-volatile storage with multiple configuration options. What this means is that the user is presented with several ways to restrict the access and use of the memory space, such as by password, physical presence of the user, and PCR states. Additionally, the memory space can be set up so that it can be written only once, not read until the next write or startup of the TPM, not written to until the next startup of the TPM, and others.

Enforced Key Hierarchy

The TPM also incorporates an enforced key hierarchy, meaning that the keys must have another key acting as a parent key (i.e. a key higher in a hierarchy) for that key to get loaded into the TPM. The authorization information for the parent key needs to be known before the child key can be used, thereby adding another layer of security.

Binding and Sealing Data

Another part of the TPM’s arsenal is the ability to bind and/or seal data to the TPM. A seal operation keeps the data contained (i.e. “sealed”) so that it can only be accessed if a particular pre-defined configuration of the system has been reached. This pre-defined configuration is held within the PCRs on the TPM. The TPM will not unseal the data until the platform configuration matches the configuration stored within the PCRs.

A bind operation creates encrypted data blobs (i.e. binary large objects) that are bound to a private key that is held within the TPM. The data within the blob can only be decrypted with the private key in the TPM. Thus, the data is said to be “bound” to that key — such keys can be reused for different sets of data.

The Armor 

So the Atmel TPM has some pretty cool weapons in its arsenal, but does it have any armor? The answer is yes it does!

FIPS 140-2 Certified 

Atmel has dozens of FIPS 140-2 full module-level certified devices with various I/O’s including LPC, SPI, and I²C. The TPM uses a number of FIPS certified algorithms to perform its operations. These standards were developed, tested, and certified by the United States federal government for use in computer systems. The TPM’s FIPS certified algorithms include RSA, SHA1, HMAC, AES, RNG and CVL (find out more details on Atmel’s TPM FIPS certifications here).

Active Metal Shield

The TPM has built-in physical armor of its own. A serpentine active metal shield with tamper detection covers the entire device. If someone attempts to penetrate this shield to see the structures beneath it, the TPM can detect this and go into a fault condition that prevents further actions on the TPM.

Why TPM?

You might be asking, “Why can’t all those functions just be done in software?” While some of the protections can be provided in software, software alone is not nearly as robust as a hardware-based system. That is because software has bugs, despite how hard the developers try to eliminate them, and hackers can exploit those bugs to gain access to supposedly secure systems. TPM, on the other hand,stores secret keys in protected hardware that hackers cannot get access to, and they cannot attack what they cannot see.

The TPM embeds intelligence via an on-board microcontroller to manage and process cryptographic functions. The commands used by the Atmel TPM have been defined and vetted by the Trusted Computing Group (TCG), which is a global consortium of companies established to define robust standards for hardware security. Furthermore, the Atmel TPM has been successfully tested against TCG’s Compliance Test Suite to ensure conformance. Security is also enhanced because secrets never leave the TPM unless they have been encrypted.

With the battle for your data being an on-going reality, it simply makes sense to fight back with the heaviest artillery available. Combining all the weaponry and armor in one small, strong, cost effective, standards-based and certified package makes the Atmel TPM cryptographic the ideal choice for your arsenal.

This blog was contributed by Tom Moulton, Atmel Firmware Validation Engineer.

Video: Vegard Wollan addresses Internet of Things security

In this video segment from my interview with Vegard Wollan, the co-inventor of the AVR microcontroller, we explore in detail the security problems you need to address as an embedded designer.

Let’s face it, it is obvious that security is a way of thinking. You have to assume bad people are going to try and hack your products. With the oncoming revolution in the Internet of Things, it is important you design the security within, rather than try to tack something on after an exploit.

The co-inventor of the AVR architecture notes that security is essential in embedded systems.

The key thing you have to know is that nothing beats hardware security. This is where the security system is implemented in silicon, storing a secret key, hash algorithms and random-number generator (RNG). Atmel makes both standalone security chips and incorporates the security circuits into some of our microcontrollers including Atmel | SMART ARM-based chips used for smart energy meters. The chips are more sophisticated than a simple IP block. In fact, there are extra layers of metal in the die so that hackers cannot probe the chip without ruining it. Many of the chips also dither the supply current, so a hacker cannot infer the code it is running by observing the tiny variations in supply current as it runs.

Atmel makes symmetrical security chips, where both the chip and the microcontroller code know the secret key, and also asymmetrical security chips, which work like that public and private keys systems you might be familiar with such as PGP and RSA security. And, note that you can uses Atmel’s tiny inexpensive security chips with any microcontroller, 8-bit, 16-bit or 32-bit, including all the micros made by Atmel’s honored competitors.

Interested in more? You can watch the entire 1:1 interview with Vegard here.

Got AES? Got security?

Currently in wide use, AES is a great algorithm that has been implemented in a number of hardware and software systems. It has been carefully studied by legions of cryptanalysts, so it’s often assumed that a system which includes AES is secure. But that assumption isn’t always true – in this post, let’s explore three situations that could cause problems.

Like all cryptographic systems and algorithms, AES depends on a key. If an attacker can get the key, he or she can impersonate the authentic party, decrypt all the network messages and generally eliminate every aspect of the system security. However, a few systems have a great place to store keys that is truly isolated from attack. With the increasing commonality of connected systems, software bugs like Heartbleed can easily find keys that you thought you had carefully protected. If you’re not familiar with Heartbleed, see this great panel from XKCD which does a nice job of explaining it.

Like all cryptographic algorithms, there are many variations to the way in which AES can be used. Lots of systems have been cracked because an improper mode, protocol or procedure was used. The illustration below shows a mode of AES which is the right answer in some cases — but definitely not this one!

The last point is a bit trickier. When encrypting something with AES, most modes require an Initialization Vector (IV). The IV should never be repeated, and in some modes it must be random. There are two problems with a repeated IV: (1) If the attacker could discover the plain text of the first message, he could determine the contents of the second; and (2), If the same message is sent with the same IV, the ciphertext will be the same both times, which could be vital information all by itself.

Problem is that it’s hard to generate a random number. One famous random number generator used the hash of an image of lava lamps – for some years an online site (lavarand) was supported by Silicon Graphics to provide online numbers.

Assuming you don’t have lava lamps and a camera in your system, you might be tempted to use ‘random’ keystrokes, noise on a signal wire, the current time to the ms, or some similar thing. Problem is, while the resulting numbers appear to be random there are often a limited number of choices. Given how fast modern computers execute, an attacker can try literally millions of possibilities in a few seconds and guess your random number!

Many designers rely on dedicated hardware cryptographic devices to help resolve this issue. Generally speaking, they offer solutions to the three points mentioned above:

• Strong protection for cryptographic keys that is not subject to bugs, malware or other aggressive attacks;
• Proper use of modes and protocols for the operations performed within the devices; and,
• High quality random number generators that rely on random physical phenomena and which are rigorously tested

Guess what? Atmel’s CryptoAuthentication devices offer all three in a low-cost small package. Start designing security in your next product with a free CryptoAuthentication tool.

Report: Cyber breaches put 18.5 million Californians’ data at risk

The recent string of major data breaches — including the likes of Target, Home Depot, P.F. Chang’s and Nieman Marcus — have spurred a 600% increase in the number of California residents’ records compromised by cyber criminals over the last year, the latest California Data Breach Report revealed.

According to the study, a total of 167 breaches were reported in 2013 – where 18.5 million personal records were compromised – an increase of 28% from 2012 where just 2.5 million records were stolen. To put things in perspective, that’s nearly half of the state’s population (38 million).

These figures experienced a large uptick following recent incidents involving Target and LivingSocial, which together accounted for 7.5 million of the breached records. Out of the incidents reported in 2013, over half (53%) of them are attributed to malware and hacking.

“Malware and hacking breaches made up 93% of all compromised records (over 17 million records). The LivingSocial and Target breaches accounted for the bulk of those records . In April, the online marketplace LivingSocial reported a cyber attack on their systems that compromised the names, email addresses, some birth dates and passwords of over 50 million customers, including 7.5 million Californians. In December, Target reported a hacking and malware insertion into its network that resulted in the theft of the names and payment card data of 41 million customers, including 7.5 million Californians,” the report noted.

Even by factoring out both Target and LivingSocial, the amount of Californian records illegally accessed last year rose 35% to 3.5 million.

“Data breaches pose a serious threat to the privacy, finances and personal security of California consumers. The fight against these kind of cyber crimes requires the use of innovative strategies by government and the private sector to protect our state’s consumers and businesses,” California Attorney General Kamala Harris said in a statement.

While California residents aren’t any more susceptible to data hijacking than others, the state law requires businesses and agencies to notify customers of any breach involving more than 500 accounts. This law led to the creation of the California Data Breach Report.

The last 12 months weren’t a fluke either. In fact, “These data breaches are going to continue and will probably get worse with the short term,” emphasized Jim Penrose, former chief of the Operational Discovery Center at the National Security Agency.

Aside from payment cards, which the Attorney General urged companies to adopter stronger encrypting and safeguard technologies, one of the most vulnerable sectors is the healthcare industry. Not only are a number of medical devices coming under siege by hackers, stolen health records are also plaguing the industry. Moreover, cyber thieves accessing unprivileged information can even be more harmful than other stolen data as it can be used for identity theft and fraud over a longer duration.

In 2012-2013, the majority of breaches in the healthcare sector (70%) were caused by lost or stolen hardware or portable media containing unencrypted data, in contrast to just 19% of such breaches in other sectors.

“By now, the problem should be obvious to anyone who is paying attention — data of any kind is vulnerable to attack by a wide variety of antagonists from hacker groups and cyber-criminals to electronic armies, techno-vandals and other unscrupulous organizations and people. The reason is simple. Yes, you guessed it: It is because data = money. To make it worse, because of the web of interconnections between people, companies, things, institutions and everything else, everyone and everything digital is exposed,” explained Bill Boldt, Atmel’s resident security expert.

To safeguard information and devices, authentication is increasingly coming paramount. As the latest incidents highlight, thinking about forgoing security in a design simply because that device isn’t connected to a network or possesses a wireless interface? Think again. The days of truly isolated systems are long gone and every design requires security. As a result, the first step in implementing a secure system is to store the system secret keys in a place that malware and bugs can’t get to them – a hardware security device like CryptoAuthentication. If a secret key is not secret, then there is no such thing as security.

Want to read more? Download the entire report here.

Infographic: 2014’s top data breaches (so far)

Dating back to last December, a string of major data breaches have affected nearly every sector, including a number of today’s most notable brands. This infographic from DataBreachToday highlights some of the most significant breaches, based on what each publicly disclosed around the incident.

Evident by the surge in cyber crime, the world has become a serious hackathon with real consequences; and, unfortunately, it is likely that it’ll only get worse with the rise of mobile communications, cloud computing, and the growth of autonomous computing devices and the Internet of Things.

So, what can be done about these growing threats against secure data? Here’s how to ensure trust in our constantly-connected world.

And, it appears that the general public is now cognizant of these threats, casting its doubts on the security of their data. With the growing number of breaches and vulnerabilities, a recent Gallup poll has revealed that Americans are more likely to worry about hackers accessing and stealing their personal information than any other crime, including burglary and murder. Specifically, 69% of these respondents claimed they frequently or occasionally fret over the notion of having their credit card information stolen by cyber criminals. These worries are justified, too. Over 25% of all Americans have experienced some form of card information theft, making it the most frequently cited crime on the infographic from Forbes below.

Secure your hardware, software and IoT devices

Evident by a recent infographic published by Forbes, it appears people are finally cognizant of the urgent need for security. It’s clearer than ever that hacking has become a real problem over the web and into electronic devices. With the emergence of the Internet of Things (IoT), we consistently find ourselves connecting these gadgets and gizmos to the web. As a result, security becomes a key issue throughout the entire chain.

Analog Aficionado Paul Rako recently had the chance to catch up with Bill Boldt, Atmel’s resident security expert, to explore the latest threats and trends in security as well as how Atmel can help secure products across the spectrum. Not in the reading mood? There’s a pretty sweet playlist of all the footage from the 1:1 interview here.

In the first segment of the interview, Boldt discusses how an engineer or designer can use Atmel’s CryptoAuthentication chips to ensure that the accessories to a particular product are genuine. Here, the security expert talks about using symmetrical authentication to certify that only a drill manufacturer’s batteries will work on its own drill.

If you recall, Boldt provided an in-depth exploration into this same demo, which can be found here. Though securing hardware is great, if you wanted, you could make this symmetrical authentication protect any kind of plug-in or device, even if it is not electronic. In fact, this safeguard is used on things ranging from ink cartridges to e-cigarettes; moreover, medical device manufactures love this technology since it protects them from liability from knockoff products.

This can help secure products with add-ons or attachments, but an even greater value for hardware security comes when you use these chips to make sure that your device has not had its code or operating system hijacked. Since the interface between the microcontroller and the crypto chip is only sending a random number from the micro, and the one-time result from the crypto chip in response, snooping on the SPI port will not help you crack the code. Now, your microcontroller firmware can query the chip and ensure that it indeed gets the proper result — if someone attacks the firmware and puts their own code, it won’t execute since it cannot get past the protected part of the chip code that has to get a valid response from the crypto chip.

You can extend this to secure downloads as well. As long as your code requires the downloaded segment to query and respond to the tiny crypto chip, only your code will work since only you know the secret key programmed into the chip.

“As a hardware engineer, I am just as fascinated by the cool packages we use as well as all the math and firmware algorithms,” says Rako.

In the subsequent video of the interview, Boldt describes the packaging for the crypto chips, in addition to a unique three-pad package manufactured by Atmel that does not need to be mounted on a circuit board at all.

During the segment, Boldt also delves deeper into some security scenarios for the IoT, incuding some great analogies. Furthermore, the security guru reminds viewers that these Atmel CryptoAuthentication chips will work with any company’s microcontroller, not just Atmel’s.

One thing you hear bandies about in security are the dissimilarities between both symmetric and asymmetric. The aforementioned drill demo was symmetric, since both the drill and the battery had the secret key programmed into the MCU and the crypto chip, respectively. Here, Boldt expands on the topic and how Atmel does all the hard math so you don’t have to worry about it.

Concluding his interview with Rako, Boldt addresses the fact that you can use the crypto chip not only in a drill, but in the charger as well to guarantee that only your OEM charge will charge your OEM batteries. The resident security expert wraps up by noticing that people can counterfeit those holograms on a product’s box, but they can’t hack hardware security chips.

Interested in learning more? Explore hardware-based security solutions for every system design here. Look to secure the full stack? You can receive a FREE Atmel CryptoAuthentication™ development tool. For more in-depth analysis from Bill Boldt, you can browse through his archive on Bits & Pieces. 

U.S. agencies investigate medical devices for cyber flaws

According to a recent report from Reuters, the U.S. Department of Homeland Security is currently investigating nearly two dozen cases of suspected cybersecurity vulnerabilities in medical devices and hospital equipment that officials fear could be exploited by hackers.

(Source: Getty Images)

The vulnerable products include implantable heart implants and drug infusion pumps, thus leaving members of the Industrial Control Systems Cyber Emergency Response Team (ICS-CERT) concerned these flaws could be used to induce heart attacks and drug overdoses, among other things.

Without naming companies, the ISC-CERT team announced last year that a vast assortment of these medical devices contain backdoors making them quite susceptible to potential life-threatening hacks. These hard-coded password flaws affected roughly 300 medical devices — ranging from ventilators and patient monitors to surgical and anesthesia devices — across approximately 40 vendors.

(Source: Shutterstock)

“The senior DHS official said the agency is working with manufacturers to identify and repair software coding bugs and other vulnerabilities that hackers can potentially use to expose confidential data or attack hospital equipment,” Reuters stated.

While there are still no known deaths as a result of such malicious behavior, officials claim that it certainly isn’t “out of the realm of possibilities,” comparing similar incidents to those seen on TV like the show Homeland. In this Showtime Network spy drama, a fictional U.S. vice president is killed via cyber attack on his pacemaker. Coincidentally enough, former Vice President Dick Cheney has revealed that he once feared a similar attack and to prevent such thing from happening, disabled the wireless connectivity of his pacemaker.

Reuters points out that security officers are increasing their vigilance around cyber threats and that medical facilities throughout the country have beefed up their networks to protect from intruders. Furthermore, the report notes that security vulnerabilities in medical devices are exposed so manufacturers can fix them, and that there was no need for patients to panic. Nevertheless, as one can imagine, this still leaves many uneasy.

As scenarios such as these continue to emerge, it is becoming increasingly clear that embedded system insecurity affects everyone and every company, not just those in the healthcare world. Products can be cloned, software copied, systems tampered with and spied on, and many other things that can lead to revenue loss, increased liability, and diminished brand equity… or in this case, injury or death. Worry no more! Thanks to ultra-secure defense mechanisms and security at its core, Atmel devices can protect firmware, software, and hardware products from future threats. Register for a chance to receive a free CryptoAuthentication tool kit here!

ECDH key exchange is practical magic

What if you and I want to exchange encrypted messages? It seems like something that will increasingly be desired given all the NSA/Snowden revelations and all the other snooping shenanigans. The joke going around is that the motto of the NSA is really “Yes We Scan,” which sort of sums it up.

Encryption is essentially scrambling a message so only the intended reader can see it after they unscramble it. By definition, scrambling and unscrambling are inverse (i.e. reversible) processes. Doing and undoing mathematical operations in a secret way that outside parties cannot understand or see is the basis of encryption/decryption.

Julius Caesar used encryption to communicate privately. The act of shifting the alphabet by a specific number of places is still called the Caesar cipher. Note that the number of places is kept secret and acts as the key. Before Caesar, the Spartans used a rod of a certain thickness that was wrapped with leather and written upon with the spaces not part of the message being filled with decoy letters so only someone with the right diameter rod could read the message. This was called a skytale. The rod thickness acts as the key.

A modern-day encryption key is a number that is used by an encryption algorithm, such as AES (Advanced Encryption Standard) and others, to encode a message so no one other than the intended reader can see it. Only the intended parties are supposed to have the secret key. The interaction between a key and the algorithm is of fundamental importance in cryptography of all types. That interaction is where the magic happens. An algorithm is simply the formula that tells the processor the exact, step-by-step mathematical functions to perform and the order of those functions. The algorithm is where the magical mathematical spells are kept, but those are not kept secret in modern practice. The key is used with the algorithm to create secrecy.

For example, the magic formula of the AES algorithm is a substitution-permutation network process, meaning that AES uses a series of mathematical operations done upon the message to be encrypted and the cryptographic key (crypto people call the unencrypted message “plaintext“). How that works is that the output of one round of calculations done on the plaintext is substituted by another block of bits and then the output of that is changed (i.e. permutated) by another block of bits and then it happens over and over, again and again. This round-after-round of operations changes the coded text in a very confused manor, which is the whole idea. Decryption is exactly as it sounds, simply reversing the entire process.

That description, although in actual fact very cursory, is probably TMI here, but the point is that highly sophisticated mathematical cryptographic algorithms that have been tested and proven to be difficult to attack are available to everyone. If a secret key is kept secret, the message processed with that algorithm will be secret from unintended parties. This is called Kerckhoffs’ principle and is worth remembering since it is the heart of modern cryptography. What it says is that you need both the mathematical magic and secret keys for strong cryptography.

Another way to look at is that the enemy can know the formula, but it does him or her no good unless they know the secret key. That is, by the way, why it is so darn important to keep the secret key secret. Getting the key is what many attackers try to do by using a wide variety of innovative attacks that typically take advantage of software bugs. So, the best way to keep the secret is to store the key in secure hardware that can protect if from attacks. Software storage of keys is just not as strong as hardware storage. Bugs are endemic, no matter how hard the coders try to eliminate them. Hardware key storage trumping software is another fundamental point worth remembering.

Alright, so now that we have a good algorithm (e.g. AES) and a secret key we can start encrypting and feel confident that we will obtain confidentiality.

Key Agreement

In order for encryption on the sender’s side and decryption on the receiver’s side, both sides must agree to have the same key. That agreement can happen in advance, but that is not practical in many situations. As a result, there needs to be a way to exchange the key during the session where the encrypted message is to be sent. Another powerful cryptographic algorithm will be used to do just that.

There is a process called ECDH key agreement, which is a way to send the secret key without either of the sides actually having to meet each other. ECDH uses a different type of algorithm from AES that is called “EC” to send the secret key from one side to the other. EC stands for elliptic curve, which literally refers to a curve described by an elliptic equation.   A certain set of elliptic curves (defined by the constants in the equation) have the property that given two points on the curve (P and Q) there is a third point, P+Q, on the curve that displays the properties of commutivity, associativity, identity, and inverses when applying elliptic curve point multiplication. Point-multiplication is the operation of successively adding a point along an elliptic curve to itself repeatedly. Just for fun the shape of such an elliptic curve is shown in the diagram.

The thing that makes this all work is that EC point-multiplication is doable, but the inverse operation is not doable. Cryptographers call this a one-way or trap door function. (Trap doors go only one way, see?)  In regular math, with simple algebra if you know the values of A and A times B you can find the value of B very easily.  With Elliptic curve point-multiply if you know A and A point-multiplied by B you cannot figure out what B is. That is the magic. That irreversibility and the fact that A point-multiplied by B is equal to B point-multiplied by A (i.e. commutative) are what makes this a superb encryption algorithm, especially for use in key exchange.

To best explain key agreement with ECDH, let’s say that everyone agrees in advance on a number called G. Now we will do some point-multiply math. Let’s call the sender’s private key PrivKeySend.  (Note that each party can be a sender or receiver, but for this purpose we will name one the sender and the other the receiver just to be different from using the typical Alice and Bob nomenclature used by most crpyto books.) Each private key has a mathematically related and unique public key that is calculated using the elliptic curve equation.  Uniqueness is another reason why elliptic curves are used. If we point-multiply the number G by PrivKeySend we get PubKeySend. Let’s do the same thing for the receiver who has a different private key called PrivKeyReceive and point-multiply that private key by the same number G to get the receiver’s public key called PubKeyReceive.   The sender and receiver can then exchange their public keys with each other on any network since the public keys do not need to be kept secret. Even an unsecured email is fine.

Now, the sender and receiver can make computations using their respective private keys (which they are securely hiding and will never share) and the public key from the other side. Here is where the commutative law of point-multiply will work its magic. The sender point-multiplies the public key from the other side by his or her stored private key.  This is equates to:

PubKeyReceive point-multiplied by PrivKeySend which = G point-multiplied by PrivKeyReceive point-multiplied by PrivKeySend

The receiver does the same thing using his or her private key and the public key just received. This equates to:

PubKeySend point-multiplied by PrivKeyReceive  = G point-multiplied by PrivKeySend point-multiplied by PrivKeyReceive.

Because point-multiply is commutative these equations have the same value!

And, the rabbit comes out of the hat: The sender and receiver now have the exact same value, which can now be used as the new encryption key for AES, in their possession. No one besides them can get it because they would need to have one of the private keys and they cannot get them. This calculated value can now be used by the AES algorithm to encrypt and decrypt messages. Pretty cool, isn’t it?

Below is a wonderful video explaining the modular mathematics and discrete logarithm problem that creates the one-way, trapdoor function used in Diffie-Hellman key exhange. (Oh yeah, the “DH” in ECDH stands for Diffie-Hellman who were two of the inventors of this process.)

Are you building out for secure devices?  Protect your design investments and prevent compromise of your products? Receive a FREE Atmel CryptoAuthentication™ development tool.

5 IoT challenges for connected car dev

Growth in adoption of connected cars has exploded as of late, and is showing no signs of slowing down, especially the vehicle-to-infrastructure and vehicle-to-retail segments. As adoption grows exponentially, the challenges in how we develop these apps emerge as well.

One of the biggest challenges to consider will be connectivity, and how we connect and network the millions of connected cars on the road. How can we ensure that data gets from Point A to Point B reliably? How can we ensure that data transfer is secure? And how do we deal with power, battery, and bandwidth constraints?

1. Signaling

At the core of a connected car solution is bidirectional data streaming between connected cars, servers, and client applications. Connected car revolves around keeping low-powered, low-cost sockets open to send and receive data. This data can include navigation, traffic, tracking, vehicle health and state (Presence); pretty much anything you want to do with connected car.

Signaling is easy in the lab, but challenging in the wild. There are an infinite amount of speed bumps (pun intended) for connected cars, from tunnels to bad network connectivity, so reliable connectivity is paramount. Data needs to be cached, replicated, and most importantly sent in realtime between connected cars, servers, and clients.

2. Security

Then there’s security, and we all know the importance of that when it comes to connected car (and the Internet of Things in general). Data encryption (AES and SSL), authentication, and data channel access control are the major IoT data security components.

In looking at data channel access control, having fine-grain publish and subscribe permissions down to individual channel or user is a powerful tool for IoT security. It enables developers to create, restrict, and close open channels between client apps, connected car, and servers. With connected car, IoT developers can build point-to-point applications, where data streams bidirectionally between devices. Having the ability to grant and revoke access to user connection is just another security layer on top of AES and SSL encryption.

3. Power and Battery Consumption

How will we balance the maintaining of open sockets and ensuring high performance while minimizing power and battery consumption? As with other mobile applications, for the connected car, power and battery consumption considerations are essential.

M2M publish/subscribe messaging protocols like MQTT are built for just this, to ensure delivery in bandwidth, high latency, and unreliable environments. MQTT specializes in messaging for always-on, low-powered devices, a perfect fit for connected car developers.

4. Presence

Connected devices are expensive, so we need a way to keep tabs on our connected cars, whether it be for fleet and freight management, taxi dispatch, or geolocation. ‘Presence’ functionality is a way to monitor individual or groups of IoT devices in realtime, and has found adoption across the connected car space. Developers can build custom vehicle states, and monitor those in realtime as they go online/offline, change state, etc.

Take fleet management for example. When delivery trucks are out on route, their capacity status is reflected in realtime with a presence system. For taxi and dispatch, the dispatch system knows when a taxi is available or when its currently full. And with geolocation, location data is updated by the millisecond, which can also be applied to taxi dispatch and freight management.

5. Bandwidth Consumption

Just like power and battery, bandwidth consumption is the fifth connected car challenge we face today. For bidirectional communication, we need open socket connections, but we can’t have them using massive loads of bandwidth. Leveraging M2M messaging protocols like the aforementioned MQTT lets us do just that.

Building the connected car on a data messaging system with low overhead, we can keep socket connections open with limited bandwidth consumption. Rather than hitting the servers once multiple times per second, keeping an open socket allows data to stream bidirectionally without requiring requests to the server.

Solution Kit for Connected Cars

The PubNub Connected Car Solution Kit makes it easy to reliably send and receive data streams from your connected car, facilitating dispatch, fleet management applications and personalized auto management apps. PubNub provides the realtime data stream infrastructure that can bring connected car projects from prototype to production without scalability issues.

Shouldn’t security be a standard?

Security matters now more than ever, so why isn’t security a standard feature in all digital systems? Luckily, there is a standard for security and it is literally standards-based. It is called TPM. TPM, which stands for Trusted Platform Module, can be thought of as a microcontroller that can take a punch, and come back for more.

“You guys give up, or are you thirsty for more?”

The TPM is a small integrated circuit with an on-board microcontroller, secure hardware-based private key generation and storage, and other cryptographic functions (e.g. digital signatures, key exchange, etc.), and is a superb way to secure email, secure web access, and protect local data. It is becoming very clear just how damaging loss of personal data can be. Just ask Target stores, Home Depot, Brazilian banks, Healthcare.gov, JP Morgan, and the estimated billions of victims of the Russian “CyberVor” gang of hackers. (What the hack! You can also follow along with the latest breaches here.) The world has become a serious hackathon with real consequences; and, unfortunately, it will just get worse with the increase of mobile communications, cloud computing, and the growth of autonomous computing devices and the Internet of Things.

What can be done about growing threats against secure data?

The TPM is a perfect fit for overall security. So, just how does the TPM increase security? There are four main capabilities:

1. Furnish platform integrity
2. Perform authentication (asymmetric)
3. Implement secure communication
4. Ensure IP protection

These capabilities have been designed into TPM devices according to the guidance of an industry consortium called the Trusted Computing Group (TCG), whose members include many of the 800-pound gorillas of the computing, networking, software, semiconductor, security, automotive, and consumer industries. These companies include Intel, Dell, Microsoft, among many others. The heft of these entities is one of the vectors that is driving the strength of TPM’s protections, creation of TPM devices, and ultimately accelerating TPM’s adoption. The TPM provides security in hardware, which beats software based security every time. And that matters, a lot.

TPM Functions

Atmel TPM devices come complete with cryptographic algorithms for RSA (with 512, 1024, and 2048 bit keys), SHA-1, HMAC, AES, and Random Number Generator (RNG). We won’t go into the mathematical details here, but note that Atmel’s TPM has been Federal Information Processing Standards (FIPS) 140-2 certified, which attests to its high level of robustness. And, that is a big deal. These algorithms are built right into Atmel TPMs together with supporting software serve to accomplish multiple security functions in a single device.

Each TPM comes with a unique key called an endorsement key that can also be used as part of a certificate chain to prevent counterfeiting. With over 100 commands, the Atmel TPM can execute a variety of actions such as key generation and authorization checks. It also provides data encryption, storage, signing, and binding just to name a few.

An important way that TPMs protect against physical attacks is by a shielded area that securely stores private keys and data, and is not vulnerable to the types of attacks to which software key storage is subjected.

But the question really is, “What can the TPM do for you?”  The TPM is instrumental in systems that implement “Root of Trust” (i.e. data integrity and authentication) schemes.

Root of trust schemes use hashing functions as the BIOS boots to ensure that there have been no unwanted changes to the BIOS code since the previous boot. The hashing can continue up the chain into the OS. If the hash (i.e. digest) does not match the expected result, then the system can limit access, or even shut down to prevent malicious code from executing.  This is the method used in Microsoft’s Bitlocker approach on PCs, for example. The TPM can help to easily encrypt an entire hard drive and that can only be unlocked for decryption by the key that is present on the TPM or a backup key held in a secure location.

Additionally, the TPM is a great resource in the embedded world where home automation, access points, consumer, medical, and automotive systems are required. As technology continues to grow to a wide spectrum of powerful and varying platforms, the TPM’s role will also increase to provide the necessary security to protect these applications.

Interested in learning more about Atmel TPM? Head here. To read about this topic a bit further, feel free to browse through the Bits & Pieces archive.

This blog was contributed by Ronnie Thomas, Atmel Software Engineer.