Grin, the Tech

Simple, privacy-focused, scalable MimbleWimble chain implementation.

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Oct 2018 - Feb 2019 Developer Funding - Yeastplume

Funding to allow Yeastplume to give full-time attention to Grin, from October 2018 - Feb 2019

Funding status

Status: Successfully Closed - ~€48,300 of €45,000 Target

Goal: Crypto equivalent of €45,000


Bitcoin donation address:


Ethereum donation address:


Monero donation address:


Source for this page (via https):

Please verify the donation addresses as shown above in your browser matches the source for this page on mimblewimble/site.

I’ve been privileged to have been able to focus on Grin full-time since February of 2018, and I hope my performance so far has been satisfactory to the community as well as beneficial to Grin and MimbleWimble development. I’ve left detailed information on my activities so far (as well as a few other random musings) in my Forum Progress update threads:

I invite you to have a look through there for precise information about what the previous funds have been used for, as well as information about future plans.

Based on experiences and feedback from previous campaigns, this campaign is organised thusly:

As always, those who wish to be listed on the Friends of Grin page will be, and I’m available as long as I’m awake on our gitter channel.

Who am I?

My name is Michael Cordner, otherwise known as ‘Yeastplume’ in Grin circles. I’m happy to make myself known partly for funding transparency reasons, and partly because I’m happy to take on some of the public-facing tasks that will inevitably come up as Grin evolves (more on that below). Also, my handle has no relation whatsoever to Harry Potter, which means journalists will forever leave me out of their Grin/MimbleWimble write-ups unless I start taking bold measures. :D

I’ve been a developer in some form or another for about 20 years now. In the earlier part of my career I did a few varied things such as a stint as a game developer at Argonaut Games in London, image-processing systems at NCR in Canada, educational software Riverdeep Interactive Learning in Dublin, and a long stint doing AML/Fraud detection systems at Norkom (now BAE). I also created an educational product series called Shakespeare In Bits, which remains fairly popular in schools (but is in no way a personal money-spinner,) and which I continue to maintain to this day on a very low-priority thread. More recently, I’ve done a lot of work in the smartcard and identity document industry, (the same technologies found in hardware wallets,) reviewing and implementing cryptographic protocols (such as PACE-CAM, SCP03 for those interested in details,) in various product libraries.

Like many technical people, I’ve been following Bitcoin/Blockchain from afar for many years. I’ve been wanting to get seriously into the technology for some time, which for me means sitting down and doing the dirty coding work. However, most projects I’ve evaluated are either not innovative enough (Bitcoin clones with bells on) or too far along for anyone new to make a meaningful difference. After coming across Grin and spending a bit of time reading about it, it was clear that this was the kind of project I was looking for; a project with very credible people behind it implementing new ideas, and with many unsolved challenges remaining. I started contributing where I could while catching up on the work and thought that’s been put into MW to date. Thus far, it continues to be one of the best learning experiences I’ve ever had, and has become a bit of an obsession, much to the continual annoyance of Mrs. Yeastplume.

What have I done so far?

I’ve been working on Grin part-time since about May of 2017. Some of the things I’ve been doing since then are (all can be considered still in progress):

What will I do?

As to what I intend to work on over the next few months, the task list is always in flux. Testnet3 has been very successful so far, and it feels like we’re hurtling towards a proper launch date… however this means there is more to do than ever! Very roughly:

In addition to this, I also intend to continue work on some of the softer tasks around Grin’s governance and promotion, which include:


The team has decided that a fair salary for an experienced developer should aim to be around the 120k USD mark. I work in Ireland and have been contracting for many years, so I interpret this as a daily rate of €450, or €9k per month. I’d consider some travel and expenses (within reason) included in this rate. The money will be paid out monthly from the campaign fund into my own consultancy company, taxed (somewhere between 40-50%), and the rest paid to me personally from there. As per our policy, money will always be paid out according to fiat rates.

The BTC address shown belongs to a hardware wallet. Both it and its recovery phrases (unmemorised) are securely stored far away from my person.

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