On the Security of Modern Cryptography

The security of modern cryptography is based on number-theoretic computations so hard that the problems are practically impossible for attackers to solve. In practice this means that approaches and algorithms to crack the cryptographic algorithms are known but with the current best technologies it would take too many years to complete an attack.

But what if a shortcut is found at least in some particular cases?

This is exactly what some researches [article, arstechnica] have just found for the Diffie-Hellman (DH) algorithm with 1024bit keys, algorithm which is one of the pillars of the security of Web transactions among many other uses. The researchers have shown that for DH with 1024bit keys there exist some parameters (prime modulus) that allow with current technologies to compute the secret encryption keys in short time. In other words, some parameters adopted in DH-1024 can contain invisible trapdoors. The only ways to securely use DH today seem to be:

  • to know how the parameters have been generated and to be sure that they do not allow for any “trapdoor”
  • or to use DH with 2048bit or larger keys.

What does this teach us about the security that cryptography provides to everyday IT?

How should we implement and manage cryptography within IT security?

Is cryptography joining the “zero days => vulnerabilities => patch management” life-cycle which has become one of the landmarks of current IT security?

How Secure are the Products of the IT Security Industry?

In the last months quite a long list of critical vulnerabilities in security products have been made public, for example in products by  FireEye, Kaspersky Lab, McAfee, Sophos, Symantec, Trend Micro etc. Wired just published this article with further information and some comments. These incidents make me think if writing secure code is just too difficult for anyone, or if there is something fundamentally wrong in how the IT industry in general and the IT Security industry in particular, is setup.

Implementing Cryptography right is hard

The security researcher Gal Beniamini has just published here the results of his investigation on the security of Android’s Full Disk Encrytion and found a way to get around it on smartphones and tablets based on the Qualcomm Snapdragon chipset.

The cryptography is ok but some a priori minor implementation details give the possibility to resourceful attackers (like state / nation agencies or well funded organized crime groups) of extracting the secret keys which should be protected in hardware. The knowledge of these keys would allow to decrypt the data in the file systems, the very issue which has been at the basis of the famous Apple vs. FBI case a few months ago.

Software patches have been released by Google and Qualcomm but, as usual with smartphones and tablets, it is not clear how many afflicted devices have received the update or will ever receive it.

In a few words, the problem lies in the interface between the Qualcomm’s hardware module, called the KeyMaster module, which generates, manages and protects the secret keys and the Android Operating System that needs to indirectly access the keys in this case to encrypt and decrypt the file-system. Some KeyMaster’s functions used by Android can be abused to make them reveal the secret keys.

This is another case which proves how it is difficult to implement cryptography right.

On Hardware Backdoors

Since at least the ’70s, the time of Multics (see eg. this old document on the vulnerability analysis of Multics security), the Orange Books, Military IT security etc., the role of hardware in IT security has been discussed, evaluated and implemented.

In the last years the discussion has risen again in particular about the possibility of hardware backdoors and malicious hardware. For example, since the publication of the Snowden documents there have been rumors about possible hardware backdoors in Intel, AMD and Cisco products.

A few days ago at the 2016 IEEE Symposium on Security and Privacy has been presented this paper (see eg. also here for a summary) describing how to implement a Hardware Backdoor called Analog Malicious Hardware which, as of today, seems practically impossible to detect.  The researchers were able to add a tiny circuit composed by a capacitor and a few transistors wrapped up in a single gate, out of the millions or billions in a modern chip, which acts as the hardware Trojan horse.

How difficult could it be to add a single, almost undetectable gate to the blue prints of a chip at the chip factory? How can be verified that similar gates are not present on a chip?

PS. 10 years ago I gave a couple of seminars in Italian about some aspects of history of IT security and I looked into some issues of how hardware must support the security features of Operating Systems; if interested some slides and a paper (in Italian) can be found here and here.

IT Security in the brave new world of Agile and DevOps

I just published a short article that can be downloaded here , about IT Security in the advent of Agile and DevOps development processes.

I tried to give a high level overview of the new opportunities and of the new and returning risks that Agile and DevOps bring to IT security management and governance. This requires that the IT security practitioners find new continuous and adaptive ways to provide to business the security of IT systems.

 

On a Kernel Backdoor and IT Security

It just became public that a custom built Linux kernel for embedded devices has been shipped and installed in production with a root debug backdoor open to anyone, see here for the announcement and for example here for some more details.

Besides the gravity of this particular incident and the difficulty of remediating it (I expect that many devices shipped with this kernel will never be updated) a couple of considerations come to my mind:

  • first of all the need for IT Security Awareness and Education starting from everybody working in IT : anybody can make a mistake or even a blunder, but there should be safety nets proportional to the risks and IT professional should always be aware of the “security” consequences of what they do;
  • the process of “bringing into production” IT products (aka Change Management) should be improved: as of today most of the time the really important test of an IT product is the final User Acceptance Test, which means that it is only important that the features requested by the final users work as expected. But this is not enough, and it is not like this in many other industries, think for example of televisions, refrigerators, cars etc. they all need to pass safety tests and be labelled accordingly otherwise they cannot be sold on the market. Why is it not like this also for IT products? As of today it is difficult to think of security standards, tests and labels common to all IT products, but it should be possible to agree on and adopt some common IT security baseline.

Monitoring Outgoing Traffic to Detect Intrusions

Monitoring outgoing traffic to detect intrusions in IT systems is not a new concept but often it does not seem to be enough appreciated, understood and implemented.

IT security defences cannot guarantee us against every possibile attack, so we must be prepared to the event of an intrusion and to manage the associated incident.

The first step in incident management is to detect an intrusion. Traditional tools like Anti-Virus, Intrusion Detection/Prevention Systems (IDS/IPS) etc. do their job but they can be bypassed. But intrusions can also be detected by monitoring the outgoing traffic.

In my recent personal experience, some intrusions have been detected and stopped because the outgoing traffic was monitored and blocked. Since the deployed malware was not able to call back home, it did not do anything and there was no damage; and since the outgoing traffic was monitored, the intrusion was immediately detected.

But monitoring the outgoing traffic to detect intrusions is becoming more and more difficult. For example attackers are adopting more often stealth techniques like using fake DNS queries. An interesting example has been recently described by FireEye in “MULTIGRAIN – POINT OF SALE ATTACKERS MAKE AN UNHEALTHY ADDITION TO THE PANTRY” . In this case, malware is exfiltrating data by making DNS calls to domains with names like log.<encoded data to exfiltrate>.evildomain.com . Obviously the DNS query fails, but in the logs of the receiving DNS server it is written the name of the requested domain, that is the data that the malware is exfiltrating.

As attackers are getting more creative to hide the back communication between malware and their Command & Control services, IT Security will need to devise more proactive approaches to monitoring and blocking outgoing traffic.

Hacking Your Phone from 60 Minutes

It is worth reading this script “Hacking Your Phone” from CBS 60 Minutes aired on April 17, 2016.

SS7 vulnerabilities are not new and should be known to the carriers. As usual the problem is on patching and implementing security measures to prevent illegal access to the network (in this demonstration they were legally granted access to SS7).

Malware and what it can do on phones, tablets, PCs etc. should be well known, at least to those who care about IT security.

NTIA Request for Comment on IoT Policies

The National Telecommunications and Information Administration (NTIA) of the US Department of Commerce’s Internet Policy Task Force, has announced a Request for Comment on the key issues regarding the deployment of Internet of Things.

This is one of the first steps towards creating some policies and / or regulations on IoT devices, and can be a very good occasion for stating clearly some security baselines.

GSMA and Security of IoT

GSMA just announced the availability of the “GSMA IoT Security Guidelines”. Potentially this could have quite a good impact on the security of IoTs. Even if GSMA speaks only for the mobile telecommunications industry, its importance in today communications market is undeniable. The idea behind it should be that companies and providers who plan to connect new IoT devices to the network, will follow these Security Guidelines to provide some level of security to the device communications, at least.

Let’s hope that this will be a first real step towards the IT security of IoTs, but first we need to read and understand these guidelines and then, in case, see if they are implemented and if their implementation will provide the expected benefits.