Intel SGX™ is dead

Intel announced that the next generations of CPUs (11th and 12th) will no longer support the SGX technology (see data sheet).  SGX is the secure enclave in Intel CPU.   The SGX isolates the program and data in its environment from the insecure Rich Execution Environment (REE).  Thus SGX-based applications could act as a Root of Trust.

At least, this was the promise.  Unfortunately, starting with Spectre-like attacks, SGX was under the fire of many interesting exploits (for instance, VoltPillager).  Thus, it seems that in its current form, SGX cannot be a trusted secure enclave.

For most consumers, the main consequence is that future PCs will not support any more UHD Blu-ray.  Indeed, the content protection standard AACS2 mandates a Secure Execution Environment with a Hardware Root of Trust (HRoT).  For Microsoft Windows, the solution was the use of SGX.  Some applications were also basing their security model on SGX.  They will have to find an alternative that is not necessarily available.  TPM offers a valid HRoT but not a Secure Execution Environment.  Current tamper-resistant software and obfuscation technologies may not be sufficient.

The fall of Titans?

Two French security researchers, Victor Lomne and Thomas Roche, published in January an impressive 55-page report.  The report describes a successful Electro-Magnetic side-channel attack on Google’s Titan security key.  They succeeded in extracting the ECDSA private key.

Titan security key is a FIDO U2F compliant key also known as Google authenticator.  It is functionally similar to Yubikeys.  Its purpose is to serve as a physical token for Two-Factor Authentication (2FA).

Mounting side-channel attacks on secure components like smart cards is “common.”  It usually assumes the attacker has samples to analyze and that the attacker can store arbitrary known secrets in the samples.  This knowledge provides some reference points during the attack.  Once the attack is fine-tuned with the samples using a known secret, it is possible to extract the target’s secret. Unfortunately, this is not true in this specific use case.  When registering, the token generates its ECDSA key pair.  The private key never leaves the token.  It is why it is not possible to back up such tokens.  Thus, it is possible to purchase Titan tokens, but not to feed an arbitrary key pair.  The researchers used an interesting methodology to overcome this issue.

They first identified the secure component used by Titan. They removed the plastic cover and identified NXP A7005.  They found out that some JavaCards have similar characteristics to the NXP A7005.  Thus, they used JavaCards using NXP P5x chips.

Using a 500µm coil with 10µm precision micromanipulators, they measured the EM signature of the ECDSA signing for both Titan and the JavaCard.  The comparison of the two EM signatures confirmed that they used the same implementation.  Thus, they concentrated their effort on the Javacard to design the exploit.  They reverse-engineered the implementation using the EM traces to guess the calculations. They discovered a sensitive leakage and could mount a complex side-channel attack.  The document details the complexity of the attack.  With 4,000 sampled signatures for 2TB of data, they succeeded in extracting the key that they fed to the smart card.

Then, they implemented the same attack on the Titan chip.  They increased the number of samples to 6,000 for 3TB of data.   They succeeded in extracting the private key.

How devastating is this attack?

  • The specialized equipment is about 10K€ (about $12K). The needed skill set is high.  On the  Common Criteria (CC) scale, it has a rating of 27 corresponding to attackers with moderate attack potential.  The corresponding chips are old and are not any more covered by CC certificates.
  • The attack requires the attacker to get the Titan key for several hours to collect the 6,000 samples.  It is not possible to clone it.
  • The attack requires opening the plastic casing.  The operation seems destructive.  For stealthiness, the attacker must be able to repackage the chip in a legitimate case.
  • The attacker needs to return the “borrowed” recased key to the legitimate owner. Else this owner may detect the loss and block the access.
  • This attack impacts not only the Titan token but a long list of components.

Thus, we may forecast that such attack would be efficient only against very high-profile targets.


The attack is an impressive piece of work.  Reading the document gives an overview of the issues a side-channel attack requires to solve. It is extremely interesting.

Diversity of implementation across different products is a costly but secure option.

Continue to use your 2FA tokens.  It is more secure than not using them.  If you lost your 2FA token, change your accounts to use a new one as soon as possible (which should be the case, independently of this attack).

Use 2FA tokens as much as possible.


Lomne, Victor, and Thomas Roche. “A Side Journey to Titan.” NinjaLab, January 7, 2021.

Attackers are smart

In 2010, Steven MURDOCH, Ross ANDERSON, and their team disclosed a weakness in the EMV protocol. Most Credit / Debit card equipped with a chip use the EMV (Europay, MasterCard, Visa) protocol. The vulnerability enabled to bypass the authentication phase for a given category of transactions. The card does not condition transaction authorization on successful cardholder verification. At the time of disclosure, Ross’s team created a Proof Of Concept using an FPGA. The device was bulky. Thus, some people minored the criticality.

The team of David NACCACHE recently published an interesting paper disclosing an exemplary work on a real attack exploiting this vulnerability: “when organized crime applies academic results.” The team performed a non-destructive forensic analysis of forged smart cards that exploited this weakness. The attacker combined in a plastic smart card the chip of a stolen EMV card (in green on the picture) and an other smart card chip FUN. The FUN chip acted like a man in the middle attack. It intercepted the communication between the Point of Sales (PoS) and the actual EMV chip. The FUN chip filtered out the VerifyPIN commands. The EMV card did not verify the PIN and thus was not blocked in case of the presentation of wrong PINs. On the other side, the FUN chip acknowledged the PIN for the PoS which continues the fraudulent transaction.

Meanwhile, the PoS have been updated to prevent this attack.

This paper is an excellent example of forensics analysis as well as responsible disclosure. The paper was published after the problem was solved in the field. It discloses an example of a new potential class of attacks: Chip in The Middle.

Law 1: Attackers will always find their way. Moreover, they even read academic publications and use them.

Murdoch’s pirates

images   In 2008, I wrote a post about “Big Gun”, a hacker who was supposed to have worked for NDS to hack competitors.  It followed a suite of lawsuits against News.

This was only a small portion of the large picture of NDS story.  With Murdoch’s pirates, Neil Chenoweth has just published a detailed description of how NDS acted to “keep ahead” of its competitors.  And the story is as good as a good spying book.  The difference is that this is real.  And unlike in Hollywood movies, morale does not win.

You will discover the dark side of News and NDS. The book is not technical (there are even some inaccuracies).  But the story is based on all the documents that were published during the multiple trials.

I do not like the style of the author.  Despite he uses real information, he is not objective and takes clearly position.  Furthermore, the two first sections are not following a linear narrations.  This makes the introduction of the “heroes” of this book difficult to follow.  Nevertheless, if you are working, or have worked, with Conditional Access providers, you will be thrilled by the book.

From the personal view, as I have met several of the early actors of this book, while we were designing videocrypt, it was a strange experience to discover very dark parts of some of them.   I was not naïve, nevertheless it was worst than my darkest assumptions.


CA guys, read this book.

SHA-3 is born

In 2005, the first serious attacks on the widely use hash function SHA-1 were published.  Researchers were able to generate some collisions.   The new generation SHA-2 was also prone to these attacks.  In 2007, NIST launched a contest to select the future replacing algorithm.  At the first round, there were 63 submissions.  The second round kept only five algorithms.   On Tuesday, NIST published the winner: KECCAK

KECCAK was designed by researchers from STMicroelectronics and NXP.  According to NIST, KECCAK won because it was elegantly simple and had higher performance in hardware implementation than the other competitors.  As it is foreseen that SHA-3  may be used in many lite weight embedded devices (smart dust, intelligent captors, RFID…) , this was a strong asset.  No surprise that its implementation was optimized for hardware; Its four fathers are working for companies designing such chipset.  STMicroelectronics is one of the leaders in secure components for smart cards, whereas NXP is the leader in NFC.  Another interesting argument is as KECCAK uses totally different principles than SHA-2, attacks that would work on SHA-2, most likely will not work for SHA-3.

On September 24, 2012, Bruce Schneier, one of the five finalists with his Skein algorithm, called for a “no award”.  Currently, SHA-512 is still secure for many years.  Thus,according to him, there was no need to switch to another algorithm.

In its announcement of the winner, NIST confirmed that

SHA-2 has held up well and NIST considers SHA-2 to be secure and suitable for general use.

Thus, be not afraid when you will still find SHA-2 in designs for the coming years.  We’re safe.  It will take several years to tame this new algorithm.  Nevertheless, NIST estimates that having a successor to SHA-2, if ever it weakens, is a good insurance policy.

Notes on PST 2012: (day 1: Innovation day)

Here are some notes on the first day of  PST2012.  These notes are personal and biased in the sense that they reflect what topics did ping me.  As such, they are not exhaustively representing the content of the various presentations.

Today’s challenges of cybercrime (E. FREYSSINET)

Eric is the head of the cyber crime department of French gendarmerie.  As such, he has a deep knowledge of today’s cybercrime as he is fighting it.

He first presented the big trends and issues:

  • Data to analyze is exploding
  • Organized crime;  interestingly, organized crime entered the game only lately.  The target that attracted organized crime was car theft that required electronic specialist due to increased electronic defense;  then, organized crime jumped to electronic money.
  • Cryptography becomes more generalized.  It has impact.  for instance, house search has to occur at a time of the day when the computer is already switched on.

Then he described more some cases.  A few excerpt:

  • Crime against children; This is one of the most important threat handled by his team (25% of the cases).  Several hundreds cases per year in France.   The best defense is the education of children
  • Attacks on IT system;  Botnets become the core element of many IT attacks.  Often individuals do the tools, and are hired by organization that install such infrastructure.   Interestingly, many SMEs are attacking each others!
  • There is a real business approach behind such crime.  Carders are offering professional sites with customer supports.  Malware is sold with a licensing approach, CMS,…

Then he presented a typical attack: the police ransomware.  A malware blocks the computer, sometimes encrypts data and display a message supposed to be issued by police claiming that you violated the law and have to pay a fine.  10% of the infected people pay the alleged fine.

Cyber Defense

Can we protect against the unknown?  (D. BIZEUL, Cassidian, Head of Security Assurance)

The focus of the presentation is on APT (Advanced Persistent Threat)

The six steps of APT:

  1. Information gathering
  2. Vulnerability identification
  3. Spear phishing/RAT installation
  4. Pass the hash protection/ propagation (for escalation)
  5. Malware and pack of tools
  6. Exfiltration

Detection of steps 3 to 6 should use reputation evaluation, Statistics and of course log.  Thus, it is recommended to have savvy IT team, cyber intelligence, IDS/IPS and SIEM & SOC.  Cyber intelligence is key.

CERT, CSIRT  (O. CALEFF, Devoteam)

Presentation of what a CERT/CSIRT is , and how it works.

Cyber defense tools: the sourcefire example (Y. LE BORGNE)

He explains how an Intrusion Prevention System (IPS) works:

  • Stage 1:  decoder of packets
  • Stage 2: pre-processor to normalize data
  • Stage 3: Rules engine

Why are there still intrusions?

  • The client side is more prevalent and it is the best place to attack.
  • File complexity is a good vector for malware
  • IDS exploitation is too complex
  • IPS needs skill for exploitation

Evolution of Snort

New pre-processors (gtp, modbus…), http compression.

>Deeper detection (cookies, javascript obfuscation…)

The message is that human is the key element.  Thus, they claim to simplify the task by focusing the reporting.


APT is more a buzz word.  It is not new.  The most important aspect is the Persistent Threat aspect.


Keynote: The authorization leap from rights to attributes: Maturation or Chaos? (R. Sandhu)

Ravi is the father of Role Based  Access Control (RBAC).   Will RBAC be replaced by Attribute Based Access Control?   In any case, we’re going towards flexible policy.  According to him, the main issue with Access Control is and will always be the analog hole.  Smile   The main defect of RBAC is that it does not offer an extension framework.  Thus, it is difficult to cope with short comings;  ABAC has the advantage to offer inherent extensibility by adding for instance attributes.

Security policy requires Policy Enforcement, Policy Specifications and Policy Administration.

He believes in Security as a Service because there will be an incentive to  properly secure stuff else you change the service provider.

SME session

Arxan (M. NOCTOR)

Nothing new.  If you don’t know Arxan, and if you need software tamper resistance, visit their site.


How to strip off a TV set?  He highlights the risk  of connected TVs that are not  secure at all, although they may handle confidential data such as credit card number.

Secure IC (P. NGUYEN)

Silicon Security;   Usual presentation on side channel attacks.   The new attacks are Correlation Power Analysis and Mutual Information Analysis (new since 2010)  The new trend is to use Information Theory realted metrics.  They have  a dual rail family with formally proved security (to be presented at CHES2012)

Smart cards, Tokens, Security and Applications

This book (Springer 2008), by Keith Mayes and Konstantinos Markantonakis (editors), provides an overview of secure chips and their applications. It mainly focuses on two types of tokens: contact and contactless. Excepted a brief introduction to Trusted Platform Modules (TPM), the book does not detail embedded IC or Hardware Secure Modules (HSM). The book depicts the major operating systems and environments (Java Card, Global Platform, MultOS…) and describes in details the application development environments for Java and SIM toolkit. The book explores different fields of application: mobile, banking, Pay TV and ID cards. A special focus is given to the mobile applications.

In my mind, smart card is strongly associated to security. Security is the absent one from this book. The book never speaks about the hacks. In the contactless field, often the transport cards are cited. Never the recent hacks have been cited. In the ID cards, never the recent problems of passports have been disclosed.

Should you read it? If you are looking for a basic introduction to smart cards, this may be one of the references to read. Thus, it may interest non-security students, people who want to have a first level of understanding, journalists… If you are looking for a good understanding of one of the domains of use of smart cards, then look for a more specialized book. If you are a security expert, definitively this book is not for you.

A more complete review is available on the IACR web site.