Sumokoin: Development Path

Two months ago, we launched Sumokoin like “just-another-cryptocurrency” to this crowded field and the rest story most of us have already known.

Like a baby in a new wild world, he met many people, a few were just scammers trying to catch a portion of anything they could. Luckily, many others were good guys who helped him through attacks and pitfalls. So, first of all, we would like thank all of you for great support.

Back to the end of 2016, there were two guys, like millions of guys working in an industrialized country with very strict culture, who would live the rest of their lives in routine, doing forever the same day job. But on a very late night of September 2016, they decided to do something different and that was the beginning of Sumokoin. They were both naive in cryptocurrency only knowing that they could publish their fork via a forum called “The Bitcoin Talk” and when the announcement came out, Sumoshi had just “newbie” account, as he had never written a single post. He’d never known that a “newbie” account would result in no images shown at his post.

He still remembers the moment he found that the announcement post looked very bad being text only, all images being replaced with ugly links, and the whole post appeared a casual work from an unknown team. Yes, that was not a happy moment. But we were actually a completely unknown team, bearing no trust from anyone and with not much hope of building a community so only through some tough challenges we could prove ourselves. And challenges came soon after….

Old Code, New Problem

Sumokoin, as a fork of Monero which itself was a fork of Cryptonote, inherits an algorithm for difficulty adjustment which, I may say, seems very optimistic regarding the good intentions of the wild crypto world. People soon found out that they could easily mine SUMO using a high hashrate without being caught up by a proportional rise in difficulty for long periods of time. The algorithm would just ignore the first 30 blocks, for a reason, and would only adjust to a proper difficulty level after hundreds of blocks mined. That could be OK for an established coin, with great total hashpower, where an increase of the total network difficulty, even by a small fraction, needs a lot of mining power. However for a small coin, using an existing, well known, hashing algo, it’s very easy to rent big amounts of hashpower (even x10 folds) to pour in and still enjoy low difficulty for hours. When the difficulty caught up with the total network hashpower, these people would just leave abandoning the network at high difficulty, essentially stealing good coins from other miners and damaging the network.

Eventually that became a serious problem, leading to a network stall for days, so team was set to find a new algorithm with better responsiveness to even the slightness of hashrate changes. Team was very reluctant to do so because that would require a hardfork to implement while we had agreed to avoid frequent hardforks that would force users, exchanges and anyone running a node to upgrade while creating uncertainty to the community.

The new algorithm, while first appearing an easy job, turned out a rather tough one. During development, especially with the great help provided by Scott (zawy12), team gradually learned a lot about what affects the validity of the algorithm like time-warp attack, Poisson distribution etc. So after over a week of (rushed) development, finally, the new difficulty adjustment algorithm could be out to deal with the real world problem. Attackers, who rent high hashrate to mine, now have very small advantage in term of difficulty adjustment delay. Luckily, the hardfork went on without a single issue and those who struggled through the bad times the network was stalled now feel very happy with the new algorithm that brings back fairness to all miners. Many thanks to the community for its patience during dev time.

GUI Wallet

From the beginning, a demand for a GUI wallet was raised in community and the team immediately recognized that not everyone would be pleased to use command-line wallet which should be really for geeks only. We also found that many coins have no GUI wallets at all and even Monero only had its first desktop wallet version after nearly 3 years. Is it so hard to create a GUI wallet?

The answer is YES. It would be very hard if you have no experiences in development cross-platform desktop application and even harder for a not-a-bitcoin-fork coin. Fortunately, team had Bill who had already developed some cross-platform GUIs in Python to take the job. The target for first version of GUI wallet was simple, intuitive and do-it-job. It should be a good looking wallet, no needs to be over-engineered, it would be a wallet for everyone.

Bill drafted the first prototype of the app very fast then team discussed on every single feature should be in GUI to keep it tidy and less clustered. A few more features he wanted to include then were set aside for next version so that the first beta could release on time. We really did not expect much from the first version, yet reaction from community were very encouraging. Here are a few quotes from forum thread:

“Wallet is really amazing and revolutionary…”


“The wallet is really very good, simple, very functional, easy to use!”

The wallet, however, still have some issues in different OSes and that’s unavoidable for the first beta product. We will surely have more improved versions in future releases.

Sumokoin GUI Wallet

Development Path

Team had a constructive discussion last weekend on development path. We now have 4 developers (and it seems a big team for an under-1M-cap coin, I’ve just known that 😉). Of course, devs are working on free time only and all already have rather busy company jobs. So, we try not to give a tight schedule and some delays may be expected to ensure good outcome quality. Here are dev tasks in the next 3 months:

** Core:

++Sub-address: Feature to create a disposable, temporary address for receiving funds without being tracked or linked to main wallet address.

  • Main dev: Haruto Tanno
  • Target release: late Aug, 2017

++Multi-signature wallet: Feature to create multi-signature wallet for team, corporate uses or for better security.

  • Main dev: Sumoshi Tanaka
  • Target release: late Aug, 2017

** GUI wallet: Next BETA release. Various improvements on UI/UX. Better logging and compatible with OSes. Support multi addresses and sub-address.

  • Main dev: Bill Aue
  • Target release: Sep, 2017

** Lite wallet: Online wallet for instant use.

  • Dev: Vu Quang
  • Target release: Late Sep, 2017 or Oct, 2017

** Sumokoin Easy Miner: A side project by Bill to make a cross-platform GUI for CPU miners with easy to start

  • Dev: Bill Aue
  • Target release: Aug 2017

For all above tasks, core development will mainly merge from upstream codes (by Monero) with modifications and improvements. Lite wallet will be the whole new job for team while GUI wallet and Easy Miner will, hopefully, create a good reputation for Sumokoin.


So, we are here, less than 2 months and half from the announcement. It’s just a baby step, yet very important one, for Sumokoin. We are, as a team, feeling much stronger, much optimistic for future development of the coin. I hope we can keep the pace and more great ideas/features will be implemented in next 6 months.

We would like to give special thanks to active and helpful community members, @sumogr, @fiexer aka Maarten Henskens and many others who has been along with us from early days and doing their best to support Sumokoin.