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Cryptographic signature: meeting cyber-security challenges of ever connected IoT devices

When it comes to IoT devices, one question arises: how to meet the cyber security challenges and protect fleets?  Many players are jumping into the juicy IoT market, ready to come up with the next best idea, and companies are placing sensors all over their buildings, machines and vehicles. They are collecting and aggregating huge amounts of data for predictive maintenance, process optimization, energy savings, autonomous machines and vehicles, and more. But with the proliferation of embedded IoT devices permanently connected to the Internet, a real security challenge is posed. A vulnerable device is also technology that can be stolen or tampered with, and more importantly, an open door to a company’s IT network. To limit this risk et protect IoT devices, the cryptographic signature is an appropriate technological response.

The cybersecurity challenges of IoT

Whether you’re using IoT in manufacturing, smart buildings, toasters or smart city applications, the connected devices pose 4 major IT security challenges:

Challenge 1: Data transmission security

The principle of modern IoT is to collect and process data to improve, monitor or automate a process. The connected devices communicate via an internal network or directly via the Internet with IT systems running in companies’ premises or in the cloud. One major challenge is to secure the data as it is transmitted from the device to the system in charge of using each piece of information.

There are 3 key principles to secure data transmission:

  • Confidentiality: only the sender and the recipient (whether they are users or software) should be able to view, store or process the data.
  • Integrity: the data transmitted cannot be altered in any way, either intentionally or accidentally. This is essential or even vital if you’re dealing with autonomous machines or vehicles.
  • Authentication: the origin and the sender are verified before transmission is completed

Challenge 2: IoT Data Protection within the device:

There is a tendency to think that cybersecurity is limited to protect the data during the transmission between a device and a system. But what if the data on device is stolen or tampered with? Imagine a health care system controlling insulin or brakes in a car. Confidentiality and integrity on device have a serious impact in the context used by the device. Hence, protecting the data or at least being notified when tampering is happening ensures the security of the context (the patient or the car to go back to our examples).

Challenge 3: IoT device safety

Beyond data, user safety is also at stake. The device software integrity should be protected to avoid public health problems, default or misuse. For example, in payment industry several standards and certifications reduce at maximum the risk of fraud and permits to offer payment services to users in heterogenous contexts. In any cases, IoT security standards recommend using robust cryptographic algorithms, but it could be a challenge to make these run in very specific contexts like low power, low cost, etc.

Challenge 4: Intellectual property protection

There is no point in developing a revolutionary device if it could be stolen or cloned by the competition. Protecting the software against attacker trying to reverse-engineer it or to steal it is preserving sometimes years of R&D and investment. Industrial espionage and counterfeiting are costing not only money to companies, but are also putting their whole business at risk if an attacker manages to replicate it thanks to an easy access to the software.

The risks being now explained, let’s see how to mitigate them. And for that, cryptography, and especially signatures, can seriously raise the bar for attackers.

What is a cryptographic signature?

Signatures relies on a public key and private key mechanism.

In public-key encryption, anyone who knows the (digital) public key can encrypt a message, but only someone with the private key can decrypt the message. Signatures work the other way around: a message can only be signed by the person who knows the private key, and anyone with the public key can verify it. With IoT, this process enables the identification of which device sends which data. The cryptographic signature works like an individual identifier and thus provides each device with an identity. However, a signature alone will not protect the integrity of the device. Both use cryptographic algorithms but they are two different things that serve different purposes.

In other words, encryption and cryptographic signatures work together: the first to protect the confidentiality and the second to authenticate and protect the integrity of the message.

Meeting the challenges of IoT with cryptographic signature

Cryptographic signature provides device authentication. It ensures that the data received is from an legitimate device.

Previously, serial numbers, a sequence of arbitrary numbers, were enough. But at the age of connected devices, faking a serial number is too simple.

Without a signature, false data can be generated, or fake devices can be set up to defraud. If we take the example of connected electricity meters, without a cryptographic signature, one could send meter data that does not exist or set up a fake meter.

Implementing cryptographic signature to identify and protect IoT devices

If companies have the competency in-house, they can handle the integration of cryptographic signatures into their IT systems and devices and then have them audited. But this is usually very expensive, time-consuming and requires competency that is rather scarce in companies. The easiest, safest and most cost-effective way to secure connected devices is to hire experts.

QShield, a solution to secure cryptographic signatures

Cryptographic keys are used to produce a cryptographic signature. Unprotected keys are usually hidden in the source code and are quite easy to find by hackers. With QShield, it is possible to implement white-box cryptography to hide cryptographic keys in software and protect connected devices and data. QShield is regularly audited and accredited by CESTI.

Thinking of securing your IoT devices by implementing cryptographic signatures? Ask for a demo !

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