The 2017 Letter That Named Identity Fragmentation Before the Vocabulary Existed

On the evening of September 11, 2017, Fatih Koç, then a designer and frontend developer at Turkish ad agencies, sent a long email in Turkish to a writer he followed. Its subject line translates as "Reasoning About Blockchain." The email is preserved verbatim in the project archive, and it is the earliest written record of the ideas that became Solidus Network. This page documents what that letter said, what happened to each of its ideas, and what it got wrong or left open.

One thing to say plainly before quoting: the letter is a personal document of its moment. Alongside the technical ideas it carries autobiography and the political commentary of its era, which are preserved in the archive and are not this page's subject. Passages below are translated from the Turkish original and quoted in relevant part.

What the letter describes

Four ideas run through it, written by someone with no blockchain vocabulary beyond what 2017 offered: the letter's author describes himself in it as "a designer who can code," unsure whether he could build any of this.

A universal, user-controlled identity layer. The letter's central passage describes, in plain language, what would later be called self-sovereign identity with selective disclosure:

A public API where people can sign up to websites, log into their phones, use services, keeping all their personal information encrypted on a blockchain. One universal username and password instead of dozens. Granular control over which service can access which piece of personal data, and a mechanism where people earn a reward each time their data is used.

There was no term for this in the letter because the terms did not exist yet in any usable form. What it describes maps onto what the industry now calls SSI and selective disclosure, vocabulary that arrived years later.

Data as an economic layer the producer controls. The letter's sharpest passage, two clauses joined here as the deck-notes in the archive also join them:

In a century where data is more valuable than oil … the fact that we, the people who produce that data every moment, in every interaction, have no say over it, is absurd.

And, in a passage about AI that has aged unusually well for 2017:

Writing the code for AI isn't the problem anymore, but finding enough data to actually train it, that takes enormous effort.

Distributed compute, storage, content rewards, and bandwidth. The letter also sketches renting out idle disk and compute ("a global supercomputer" built from personal machines), rewarding user-generated content, and peer-to-peer bandwidth sharing, naming Filecoin, Storj, Golem, Steem, IPFS and LBRY as the fragmentary attempts of the day, and criticizing the field's pattern: projects that "raised millions in ICOs but operate in narrow domains," without "an integrated vision."

And one problem it admits it cannot solve. On the question of a reward mechanism that would actually reduce inequality rather than reproduce it, the letter stops and says so:

Frankly, I haven't been able to settle anything on this.

What happened to each idea

The honest ledger, nine years on:

• The compute, content-reward, and bandwidth threads were cut. Solidus chose identity-first. The validator network that exists is distributed for consensus, not general compute. Those threads survive only as documented past consideration.
• The unsolved thread is still unsolved. The letter's admitted gap, a credential-usage reward mechanism that serves the person the data describes, remains open in the 2026 stack. The archive's own cross-reference says exactly that. A documentary page earns nothing by pretending otherwise.

Why the timing argument matters, and what it is not

The argument this page supports is narrow, and it is not "the founder was early." Being early is not an achievement; the graveyard of decentralized-identity projects is full of early. The argument is about legibility: the problem was legible in 2017, the standards to solve it only became legible between roughly 2019 and 2024. Verifiable Credentials became a W3C Recommendation in November 2019. DID Core followed in July 2022. SD-JWT-based credentials took shape at the IETF in the years after. eIDAS 2.0 (Regulation (EU) 2024/1183, in force since May 2024) turned user-held digital identity from an idealist's sketch into a legal requirement arriving on a schedule. A 2017 email could name the need; nothing in 2017 offered the pieces to build it interoperably. By the mid-2020s, the pieces existed and were someone else's well-specified standards, which is precisely why Solidus composes rather than invents, and why the letter's ideas became buildable at all.

What the sequence proves, and pointedly does not prove, is taken up in Nine years, no pivot.

The artifact

The email exists in full, in Turkish, dated September 11, 2017, 19:48, preserved unedited in the project archive with its 2026 cross-references. This page quotes it in relevant part rather than republishing it; the letter is a primary source, and primary sources deserve to be read as they were written, personal, political, uncertain, and, on one thread out of four, right in a way that took nine years and other people's standards to become checkable.