This year the Financial Crypto and Data Secure Conference did a little detour from its usual venue and came to Asia, and for the first time to Malaysia. From Japan it takes a night flight to Kuala Lumpur and then to Kota Kinabalu in Borneo. Only a night flight is ok to take. A trip to the other side of the planet, that is, to the Caribbean, would be a different story to attend it.

Despite the COVID19 outbreak in the region and all the constraints it brings, several researchers made to Malaysia, although there were a few absences which the FC chairs managed to mitigate by asking the authors to record the presentations, and even call the them via Skype for Q&A after the talks.

Talks

There were a couple of talks that drawn out attention because we are more closely looking into to, specially those related to payment channels, including a SoK paper similar to one we released last year on Eprint.

During the poster session I was surprised by one of the works because the author explained he relied on a technique that ``programs the generic group model’’. The reason of my surprise is that I have a work from 9 years ago that introduces programmability in the Generic Group Model. Needless to say I was glad to see it being used (not sure, if it was cited though).

Two other works that I plan to check are about privacy-preserving atomic swap by Deshpande and Herlihy, and uncooperatively closing of payment channels by Nagamine and Matsuura. The former was also presented at SCIS 2020.

IOHK

We also had a few works by my colleagues from IOHK:

• Dionysis Zindros - Non-Interactive Proofs of Proof-of-Work
• Kostis Karantias - Proof-of-Burn
• Alexander Nemish - Marlowe
• Alexnder Nemish (on behalf of authors)- The Extended UTxO Model

More pictures!

Terima kasih, Malaysia! It was a really good week down there. i even had time to work in a Crypto submission. Fingers crossed!

Today I had a meeting with the other Brazilian researchers and professors based in Japan. Including an old friend, like Prof. Claus who is a fellow student in Tokyo, and now is based in Tsukuba. The motivation of the meeting is to strengthen ties between the research community in Japan and the embassy, and was attended also by the Brazilian Ambassador Eduardo Saboia.

We could not deviate from the topic of the COVID-19 and how it is affecting researchers and students during their study period in Japanese universities. Later we discussed ways of increasing the number of researchers here, as well as ways of coordinate this community towards to show to the Brazilian community in Japan how we help Japan by improving science.

Gabriela Resendes from the embassy organized the meeting, and I find it very exciting that our embassy took the liberty to start this discussion. I hope we continue these discussion calls in the future, and eventually we could organize a small conference or workshop with the several branches of science that there are Brazilians working here.

I am particularly interested in showing to all Brazilian communities in Japan that we have several Brazilians working with science and technology here. It seems that not so many of our countrymen know about that. In particular, the little Brazilian children growing here. Once I had been asked, to my surprise, in one of my classes by a Brazilian student when he discovered I am Brazilian: “Oh, is there many Brazilians working with technology here? I thought there isn’t many…”

I believe we can change that by showing our (academic) example, and I am glad that, apparently, the embassy noticed that too.

The Participants

On the side of the Embassy

• Gabriel Resendes
• Leandro Napolitano
• Camilo Prates
• Francisco Cannabrava
• Eduardo Saboia

On the side of researchers:

• Claus Aranha
• Ingrid Lima
• Marcos Masukawa
• Myself

I’m here to attend SCIS 2020, and Kurazumi, a student in our research group at Tokyo Tech, is here to present his work on multi-hop payment channels.

His work develops on the work of Maravolta et al. (NDSS’19) which observes the weakness on HTLC based payment channels. The basic idea of the so called Warmhole attack is that during a payment channel composed by several hops, at least two nodes in the channel can collude and collect payment fees from all the nodes in between the two malicious nodes. Since the two nodes collude, they can share the pre-image value used in the HTLC. Maravolta et al. approach is to pick an independent value for any pairwise channel.

Our approach is to improve in the computational complexity of the their protocol by substituting the used ECDSA protocol, by a newer and more efficient one, namely the one by Doermer et al. (S&P’18). This substitution required a few adaptations from the original scheme from the multihop scheme in Maravolta et al., and this is our contribution.

More than that, please wait for the full version yet to be submitted to an international conference.

Instead you can enjoy the pictures of the event and the Kochi Castle nearby the venue.

Happy New Year!

This is Mount Fuji in the last day of 2019.

I have been thinking about revisiting my old blog for quite a while now. More than that. The idea was to turn it into a central point to gather information about my activities. A few students and colleagues had told me, to my surprise, that was hard to find information about myself online.

These comments lingered in my mind and added up with my personal concerns that I needed to give more visibility to my research and professional interests. The problem was to set some time apart to brush out my skills of “web design”.

Two weeks of vacation solved that and now I have a website: Mario Report

Meeting with Mario Borges the President of the Brazilian National Council for Scientific and Technological Development (CNPq) in the Brazilian Embassy in Tokyo.

We had a chance to chat about the actual state of the research in Brazil with Japan based scholars.

It was a great chance to travel to China to attend the World Economic Forum during the Annual Meeting of the New Champions in Tianjin.

Funny thing is that I ended up being part of a NHK TV Show and later in the month my Japanese friend recognized me and send the me picture below.