Airport Economic Value study published!

The Modelling Airport Economic Value Study recently published (link here) has been made by the University of Westminster (Andrew Cook, Gerald Gurtner, Graham Tanner and Anne Graham) and Innaxis Research Institute (Samuel Cristobal), supporting EUROCONTROL (Denis Huet and Bruno Desart) within SESAR Project 06.03.01. The study provides a better understanding of the interdependencies of various key performance indicators (KPIs) and assesses the existence and behaviour of an airport economic optimum, in a similar way to the early 2000s, when estimating the economic en-route capacity optimum.


By gathering for the first time real operational, financial and passenger-satisfaction-related data over 32 European airports, it was possible to develop and calibrate a model which produces reliable and realistic results. The fully calibrated results show the presence of a trade-off between the cost of extra capacity and the increase in the number of flights operated. As a consequence, all 32 airports exhibit a maximum in net income as a function of capacity, when the marginal cost of operating extra capacity is sufficiently low. This threshold in the marginal cost is, however, rather different across airports, and only a few airports can sustain a high cost of capacity: these are the largest and most congested airports, which clearly need extra capacity. This threshold is roughly consistent with the airports’ current operational cost of capacity, which means that they should be able to manage this growth, subject to the availability of investment.

The team has also developed a tool that provides access to all the features of the mathematical model with out having to dig into the equations. The underlying mathematical module is written in Python, while the interface is written in Matlab. The communication between the modules is transparent to the user and the software is capable of auto-calibrate the airport model using the existing or new data. The tool is flexible to explore the parameter space and different views of the output variables can be selected for a better understanding of the model outcomes. Results can be saved then in common format for further use (txt, csv, png, fig, etc.)

Screen Shot 2017-02-01 at 13.59.56 sample2122 blog_post32143


We warmly invite you to read the full report here!

Congrats to Samuel/UoW colleagues for such a superb study 😉


Secure information sharing – secure multi-party computation in air traffic management

Easing confidentiality between business rivals through a clever use of mathematics

Secure Multi-party Computation is the preferred technique when multiple parties have to perform a computation, yet do not want to share private, confidential data. SecureDataCloud, the first research project about the application of SMC in air transport, has been recently completed by a team led by Dr. Zanin. The foundations of this technique are valuable for potential applications in the context of cyber-security, air transport and other domains.

The history of cryptography, i.e. the study of techniques for secure communication in the presence of adversaries, is fascinating and has been linked to social and cultural changes. Over two thousand years ago, the Caesar cypher was the state of the art. It involved an alphabet shift with a constant key, such that “abc” may be encrypted to “bcd”. This concept, while in actuality very simple to understand in present day, was a novel technique in the days of the Roman Empire.

Then, a substantial change in technology occurred in 1553, when the Vigenère cipher was invented by Giovan Battista Bellaso. This new cypher relied on a large key word, which controls the letter substitution depending on the letter used from the key word. If the key word is long enough, ideally, as long as the message itself, this schema is secure. The challenge of transmitting a long secret key was to use sentences from books that were owned by both the sender and the receiver, which in those days was less probable.

The most progress made in the cryptographic evolution has been achieved in the last decades, through the development of Secure Multi-party Computation (SMC) techniques. Previously, the scenario involved two parties trying to maintain privacy against an external adversary. However, in many modern applications, two or more parties need to maintain their privacy against each other, not just external adversaries. Yes, they still need to collaborate to exchange critical information, which is a significant change in the information security framework.

Secure computation was invented by Andrew Yao in 1982, and can be exemplified by the following problem, as originally proposed by Yao himself. Suppose two millionaires, Alice and Bob, are interested in knowing which is wealthier yet they do not want to reveal their actual wealth. To put in a different way, both parties (Alice and Bob) possess some information, respectively represented by A and B; the SMC problem is then an evaluation of a function C = f(A, B), such that at the end both Alice and Bob get to know C, but they don’t gain any additional information about A and B.

Many solutions have been proposed in the last 30 years enabling the evaluation of (almost any) functions. The mathematics involved in such computations could be complex and the computational cost associated with SMC protocols is high. Just to give an example, the secure two-party evaluation of an Advanced Encryption Standard (AES) encryption was achieved in 2007 (Lindell and Pinkas, 2007) but the computation takes around 20 minutes. Using SMC to access your bank account could be really secure but access to the information may take 20 minutes.

Innaxis started working on solving certain information-sharing paradigms in Air Traffic Management (ATM) using SMC in 2012. In these scenarios, different stakeholders must share information to reach a common goal, as mandated by the concept of Collaborative Decision-Making (CDM). Such information may be confidential and parties may not be comfortable sharing them due to high risk and confidentiality. For instance, considering the case of slot trading, airlines may be interested in trading slots, but revealing their target price is tantamount to giving away business information (i.e. the business value of that slot, the number of passengers they expect to allocate there, and so forth). Other applications of SMC could enable the exchange of safety information; exchanging the number of certain safety critical events might be beneficial to all airlines, but this kind of information is confidential and very sensitive and would better be shared through a SMC protocol.

Can these problems be solved by a trusted “neutral-party”, which is in charge of managing the information and ensure no ill-conceived analyses are executed? Possibly, but you have to find and trust the information maintains confidentiality within the neutral-party and ensure the security of the communication links in the transmission of the data. Additionally, having a single entity with access to every piece of data makes the system very vulnerable to cyber-attacks.

Starting from these considerations, we decided to start a research line concerning the use of SMC within air transport. The SESAR programme of the European Union recognised the value of this and financed the research project SecureDataCloud. We addressed two important problems: the trading of airport slots by airlines, and the calculation of delay statistics, both processed in a secure way.

The reader may refer to the several publications that resulted from this research work, with concrete implementation details that take address and solve the mathematical and computation challenges. Specifically, (Zanin et al., 2013) outlines the main ideas beyond the project and how SMC could be applied to ATM. (Zanin et al., 2014) and (Zanin et al., 2016) study a parallel problem, i.e. the creation of a secure CO2 allowance trading mechanism. Finally, (Zanin et al., 2015) deals with the problem of creating a secure trading mechanism for airport slot allocation.

Massimiliano Zanin will present SMC for air transport applications in the forthcoming Eurocontrol Cyber-security workshop, next March 23rd in Toulouse. If you need more details, about this talk or SMC in general, please feel free to contact Massimiliano, at



Y. Lindell and B. Pinkas, “An efficient protocol for secure two-party computation in the presence of malicious adversaries,”Eurocrypt 2007, vol. Springer LNCS 4515, pp. 52-78, 2007.

Zanin, Massimiliano, et al. “SecureDataCloud: Introducing Secure Computation in ATM.” SESAR Innovation Days,Stockholm (2013).

Zanin, Massimiliano, et al. “Enabling the Aviation CO2 Allowance Trading Through Secure Market Mechanisms.” SESAR Innovation Days, Madrid (2014).

Zanin, Massimiliano, et al. “Design and Implementation of a Secure Auction System for Air Transport Slots.” Services (SERVICES), 2015 IEEE World Congress on. IEEE, 2015.

Zanin, Massimiliano, et al. “Towards a Secure Trading of Aviation CO2 Allowance”. Journal of Air Transport Management, in press, 2016.

Innaxis at SIDs 2015

Every year we are excited to participate in the SESAR Innovation Days (SIDs) 2015, organised by Eurocontrol and the SJU, which will take place this year in Bologna, Italy. In 2015, Innaxis has been particularly busy in long term aviation research and as in previous SIDs, we will be continue to be especially engaged during the event. We look forward to discussing many innovative research topics and provide an update on Innaxis’ efforts. These include:


  • The ComplexWorld network has greatly evolved within the last five years. On the first day of SIDs, the network coordinator, Paula Lopez, will present an overview of the ComplexWorld evolution since it was launched with special emphasis on the key 2015 outcomes and 2016 initiatives. Please feel free to reach out to Paula ( if you are interested in obtaining more information on the network activities.
  • At Innaxis we have been working on new air transport metrics and indicators for the last few years. We have been crafting a tool to compute those metrics against real traffic data along with advanced visual tools to help understand these complex metrics. On the day before SIDs officially commences, Monday Nov. 30, we will be hosting a workshop on air transport resilience metrics: The 2015 Resilience2050 Workshop. Additional information along with free registration can be found here. Please contact Hector Ureta ( for further information on the workshop and/or resilience research.
  • The EC four hour door-to-door challenge warrants more effort to bring everyone on the same page. Building new modelling tools, metrics and data analysis capabilities will help to understand how we may achieve this goal. Innaxis has strong expertise within Mobility, with coordination efforts in the Horizon 2020 Coordination and Support Action DataSET 2050, along with the most recent SESAR-CASSIOPEIA agent-based modelling framework. These research initiatives may be of interest to you if you are working with mobility. Please do not hesitate to contact our architect of mobility tools for ATM, Samuel Cristóbal ( and Jorge Martin ( who will be at the conference.
  • Exploring trade-offs between different stakeholders has always been one of the main research priorities within Innaxis. For this particular SIDs Innaxis has liaised with the University of Westminster and Belgocontrol to present the paper “Controller time and delay costs -a trade-off analysis”. The paper will be presented within the technical sessions of the SIDs.
  • Data Science has also been an area of major interest at Innaxis over the last few years. We are working on different elements of a big data / data science infrastructure to enable major data mining efforts within Air Transport, including: current delay propagation evaluations, airport and airline resilience against disturbances, and an evaluation on new paradigms for safety monitoring, all of which is contingent on powerful deep analytics. We have advanced very far in this area, for which we are very proud. Our colleague Massimiliano Zanin will be at the conference and can speak to these efforts. Feel free to contact him at
  • In addition, complex network theory has also been prioritised within Innaxis’s research efforts and has been increasingly used to study the air transport system by defining static or dynamic structures to characterise how airports are connected. Our ComplexWorld PhD student, Seddik Belkoura, will present a poster entitled “A young person’s guide to the reconstruction of air transport networks” depicting how the sampling processes intervening in the construction of such structures can affect the topological stability of the final system’s representation. Please, contact him if this is of your interest (
  • Information Management has also been an area of interest for us. In particular, we think Data Science paradigms can only be fully enabled if data is transparently shared across stakeholders, which can only be achieved with the right secure and encrypted mechanisms are put in place. Related to this, the Innaxis team will present a talk about the main results of the SecureDataCloud project. Again, please reach out to Massimiliano Zanin should this be your area of interest.
  • Last, but not least, we will also serve as SIDs rapporteurs and help Eurocontrol extract some conclusions as well as provide our own views on future research avenues. Carlos Alvarez will lead this during the closing session. Please, contact Carlos ( if you’d like to continue the conversation!


We hope we have many opportunities to interact next week and hope you find our activities interesting and motivating for future initiatives.
See you soon in Bologna!

2015.04.07 Resilience in SESAR2020


The event “Complexity Challenges and Opportunities in SESAR2020” took place in Brussels, 7th April 2015 in Eurocontrol headquarters, organized by the ComplexWorld Network – the long-term research network supported by SESAR and coordinated by Innaxis.

In this event, there was a particular session on Resilience in Air Transport, with several Resilience2050’s consortium members presentations (ITU, Innaxis, NLR). The session was chaired by Gokhan Inalham (ITU)

Presentations available in the links below:

Innaxis participation at the SIDs

The 4th SESAR Innovation Days (SIDs), organised by Eurocontrol and the SJU, are next week: this year taking place in Madrid! In 2014, Innaxis has been particularly busy in the Air Transport research field and, just as in previous editions, we will be especially active during the SIDs. With the goal of warming the different research areas, and sharing with you open opportunities, this post aims to give you a small briefing on how we are participating in this event:

– ATM Resilience workshop:  After more than two years of hard work, the Resilience2050 FP7 project, coordinated by Innaxis, is achieving interesting results. We will be happy to welcome there all those researchers interested in sharing outcomes about this fascinating research thread. It will be celebrated during SIDs day “0”, Monday 24th,  14:00-18:00, at SIDs´premises. Please contact Hector ( to expand this info.

– The SESAR-WPE ComplexWorld network has gone a long way in the last four years. Paula (, the network coordinator, will be delighted of providing details of the 2014 activities (Workshops, CWWiki, DataScience event) and future initiatives (Book publication, Conferences). Please, do not hesitate to talk to her if you are interested in the network

– At Innaxis we have been working on Passenger-Oriented Metrics for long, crafting tools to identify, compute and analyse those metrics focusing on the 4 hour door-to-door challenge of FlightPath2050. Challenge now present in all strategic agendas, including Horizon2020 and SESAR2020.  Given our role either leading or participating in key FP7, H2020 and SESAR projects, feel free to contact Samuel ( if interested in this topic!

– At the SIDs we will show a poster of the concept of Dynamic Cost Indexing (DCI) and its relation to the four-hour door-to-door objective using the CASSIOPEIA Agent Based Modelling (ABM) simulation platform. The CASSIOPEIA platform demonstrated high potential on a first SESAR WP-E project which, after completion, was awarded with an extension to continue further investigation and improvements. If you happen to be interested in the topic, please reach Alberto Blanch ( for details.

– We are very proud of our advancements in Data Science which has been a pivotal area at Innaxis during the last few years. In May we organised the second Data Science Workshop for Air Transport, which was held in Paris-EEC. Currently, we are working on different elements of an infrastructure to allow major data mining work for Air Transport on different fronts; from evaluating current delay propagation or resilience of airports and airlines against disturbances, to identifying new paradigms on safety monitoring, all of which is based on powerful data analytics. Both David ( or Hector ( will be happy to discuss about this topic.

– Innaxis, together with University of Westminster will present a paper based on their ComplexityCost SESAR project. The paper defines a framework to assess the cost of resilience during a disturbance. The framework allows performance assessment as a function of differential stakeholder uptake of strategic mechanisms designed to mitigate disturbance. Advanced metrics, cost- and non-cost-based, disaggregated by stakeholder sub-types, are also presented.

– Innaxis is leading a pioneering project on Secure Computation applied to Aviation. Our researcher Massimiliano ( leads the SESAR project: “SecureDataCloud”, or SDC, which will be presented during SIDs in several formats:

->  SDC Talk. In this talk, we are going to explain why and how Secure Multi-Party Computation techniques can be used to improve several air transport aspects, thanks to the ability of compute information in a secure way.

-> SDC is also planning to present a demonstrator. It will be composed of a set of laptops running a software framework performing a secure computation in real time: all SID participants will then be invited to play with the system and perform auctions!

-> Two SDC posters will be presented, describing the two Case Studies that are being developed in the project.

– Last, but not least, Seddik Belkoura ( will take part of the CW-Phd session. On his paper he analyses how the use of the average and standard deviation of delays may provide incomplete intelligence to assess air transport system performance and evolution. Also, the alternative proposed way to look at delays naturally explains its heavy tailed nature without the need of emergent phenomena.

We hope you find our activities interesting and motivating while bringing you new interacting opportunities.

See you soon in Madrid!


SESAR Newsletter features Innaxis in Long Term and Exploratory Resarch

The fall publication of the SESAR Magazine has been posted on the SESAR website! For the first time, this edition is fully dedicated to the Long Term and Exploratory Research programme and highlights some examples of successful projects and networks developed under this framework. Included in this feature is Innaxis and its coordination of the ComplexWorld Network; illustrating the high visibility of the Network’s activities within this programme largely due to the results achieved.

Innaxis has been involved in two of the projects selected for publication: CASSIOPEIA and POEM. Innaxis coordinates the CASSIOPEIA project, which aims to develop a theoretical framework and a demonstrative software platform that increases the understanding of the cause-effect relationships between Air Traffic performance drivers and performance indicators.  POEM, or the Passenger-Oriented Enhanced Metrics project, is led by the University of Westminster in partnership with Innaxis. POEM establishes a new passenger-centred performance framework and simulation model for air transport. Additionally, POEM was awarded with one of the two “Most Outstanding SESAR Project” prizes during the SESAR Award ceremony in 2014.

Innaxis also coordinates the ComplexWorld network which addresses how complexity science can contribute to understand, model, and ultimately drive and optimise thebehaviour and the evolution of the ATM system that emerges from the complex relationships between its different elements. ComplexWorld has also succeeded in the development of a solid and open research community, the ComplexWorld Wiki, which builds together a common knowledge platform of the field.

We encourage members of the ComplexWorld network and those unfamiliar with the activities of Innaxis to read the SESAR magazine. This edition has great information on the SESAR Long Term and Exploratory Research programme, which will shape many research projects in the future.

Resilience metrics: input for SESAR projects


Deliverable D3.2 included sound results in the field of Resilience Metrics that were worth disseminating. In the context of this deliverable, an Annex “D3.2 AnnexIII,” was created summarizing the key results obtained targeting readers who were not necessarily familiar with the project. This material was circulated by Marc Bourgois (Eurocontrol) among others in the following activities:

-SESAR WPE projects related to Resilience and/or Robustness

-SESAR “Scales” project

-DeepBlue and SINTEF (Research companies working partially with Resilience concepts)

Resilience2050 consortium is delighted to know the research done within Resilience Metrics is becoming useful for further research!

Applying Resilience Studies to Real World ATM Challenges at Innaxis

Our newest team member, Hector Ureta, tells us what it has been like working at the Innaxis Research Foundation and Institute in his first 6 months, and the evolving application of the concept of resilience beyond its original roots.

In some weeks I will reach my “semiversary” at Innaxis – a reference the team here make to the milestone of reaching a half year tenure. I am very proud to be working with the super-professional team here and felt it was time to contribute to the team’s blog and share my experience at the organisation so far. One of the things that attracted me to Innaxis, and that I have found very rewarding at the organisation, is our work in applying the concepts of resilience to ATM.

During my Aeronautical degree ‘resilience’ was described as the ability of a system to recover under abnormal conditions, generally in regards to material properties. The term usually appeared in subjects together with defining terms such as “Structures”, “Materials” or similar. Studying those subjects involved repetitive exercises that required the analysis and calculation of permanent and transient deformations after a given stress. We were required to repeat the same exercises again, this time with software, such as Catia, after some basic programming sizing the material, specifying its properties and the stress held. In short, its application and study was fairly limited.

Air Traffic, or simply ATM when referring to Air Traffic Management, was challenging in a different way, but was studied under completely different, distinct, subjects. Despite the economic crisis, airspace demand in Europe continues to grow, which lead to a focus on efficiency as the main goal of resources usage and management.

It is nice to learn new things every once in a while…[especially] when that learning takes the form of adapting previous knowledge acquired in a completely new way to a different field

My collegue Alberto wrote in his post on this blog, “It is nice to learn new things every once in a while”. I would like to add my wholehearted agreement to that sentiment and that this holds particularly true when that learning takes the form of adapting previous knowledge acquired in a completely new way to a different field. While studying, I could never imagine myself applying the material Resilience concept to ATM. Today, I not only see the clear connection but also recognise a knowledge gap and opportunity for advancement in better developing this concept within ATM. Resilience, not just efficiency, offers great opportunities to improve ATM performance.

The Air Traffic system is of a complex nature, with huge amounts of technical systems and human operators involved. Operating close to 100% efficiency, in the view of the majority of my ATM Professors, makes the ATM system sensitive to disturbances and thus vulnerable to disturbances outside our control. The complexity of the system amplifies the problem, augmenting the impact of disturbances on their way through the different ATM layers. However, over sized system buffers would decrease efficiency to unacceptable levels. Hence, a balance between efficiency on the one hand and resilience on the other is required.

Working together as a team in search of ATM Resilience is a truly wonderful and unique experience

Innaxis is leading an ongoing FP7 collaborative project  “Resilience2050” regarding these issues. The main aim is to achieve a deeper knowledge of the  resilience concept in ATM in pursuit of a more efficient and resilient future in ATM systems. Working directly with this project is challenging, interesting and has given me the opportunity to work with an exciting international consortium of world-wide  experts, not only in the Resilience concept applied to other, non-ATM, systems, but also in data mining. This team incorporates experts from academia, ATCos and top-class aviation research centers, from countries as diverse as Germany, The Netherlands, Turkey, England and Spain. Working together as a team in search of ATM Resilience is a truly wonderful and unique experience and I hope to share some of those experiences with you in posts over the coming months as we continue to address the challenges of the task and encounter both highs and lows.

I hope you have been resilient enough to reach this blog post end, Thank you all! Hector

First ComplexWorld Annual Conference


ComplexWorld will held the first Annual Conference in Seville on July 6-8, 2011 and it will be hosted by the School of Engineering of the University of Seville.

The ComplexWorld Annual Conference is intended as a forum for Air Traffic Management scientists and PhD students, Complexity Science researchers and the ComplexWorld Network community, including Members, Participants, and SESAR WP-E investigators.

The aim of the Conference is to bring together researchers from academia, research establishments, and industry that share common interests and expertise in the field of ATM Complexity Management that lies at the intersection of Complexity Science and ATM.

The Conference will focus on new concepts and developments in areas aligned with the WP-E research theme ‘Mastering Complex Systems Safely’ which explores how Complexity Science can contribute to understand, model, and ultimately drive and optimize the behaviour and the evolution of the ATM system that emerges from the complex relationships between its different elements.
The topics of the Conference include (but are not limited to):
  • Multiple spatio-temporal scales in ATM
  • Non-determinism and uncertainty in ATM
  • Emergent behaviour in ATM
  • Complex modelling of the ATM system
  • Validation and Verification of Complex ATM models
  • Design, Control and Optimization of Complex ATM models
  • Applications of Complex Systems to improve ATM performance
  • Characterization of Disturbances in ATM
  • ATM Resilience: Analysis of disturbance propagation and system stability and agility
  • Information management and decision-making mechanisms in ATM
  • Metrics at different scales, ontology and measurement in ATM
  • Other complex socio-technical and/or transport systems.

Written contributions to topics mentioned above or similar ones are sought. Papers with innovative ideas and/or technical progress will be preferred. Please submit your abstract (one A4 page) to Deadlines:

April 1: Abstract submission deadline
April 18: Notification of acceptance
June 1: Full Paper submission deadline
July 6-8: Conference

We hope that this information is of your interest and encourage you to send a Paper and to attend the First ComplexWorld Annual Conference.

Escuela Superior de Ingenieros
, Camino de los Descubrimientos 41092 Sevilla, Spain (See the map)

Anyone interested in registering should contact Innaxis by e-mail ( including the following information:
– Name and institution:
– Arrival and departure days.

The ComplexWorld Network releases first draft of White Paper + Call for PhDs


A first draft of the Complex ATM White Paper has been finished. This first draft of the White Paper will be presented and discussed during the WP-E Networks Joint Session at the INO 2010.

The ComplexWorld Network will soon be opening a private space within Innaxis´s collaborative wiki-like site so as to share with all Network Participants additional, useful information (e.g. pointers to the White Paper references). More news regarding this will be published next week.

In addition to the first draft of the White Paper, the Network has officially opened the Call for PhDs. The Call is open to anyone who is aiming to start a PhD in a theme related to the ComplexWorld Network. The Call will be closing on December 1st, 2010.

If you have not done so already, please remember to join the Network´s  LinkedIn Group. It is a great way to engage in discussions and network with other Participants.

Finally, if you are not a Participant and you are interested in receiving the White Paper and the Call for PhDs, please contact us about formally registering your entity. The Network is opened to all types of entities that would like to join in this collaborative initiative. Questions or comments can be sent to:

Connect with us!