Provable Solvency Report #40 – July 2017

Coinfloor is a custodian of client bitcoins and we believe that we must set the industry standard for transparency and regular audits. Without proper public accountability, the industry will not be able to grow and mature. This is why we are committed to releasing a Provable Solvency Report every month. Coinfloor is proud to have the longest standing track record among bitcoin exchanges in regards to auditing.

Today we are publishing our 40th monthly Provable Solvency Report with step-by-step validation instructions for your convenience.

As of today, Coinfloor holds a total of 5,216.3059 XBT on behalf of our clients. You are invited to verify that your held bitcoins are included in this balance by following the instructions below.


What does the Provable Solvency Report include?


We started out by creating an obfuscated report of all current client balances (the Solvency Report) and then generated a SHA-256 hash of this report.

We then created a bitcoin transaction to ourselves, that includes all currently held client bitcoins, for a value of 5,549.5441 XBT and included in the output script the OP_RETURN of the SHA-256 hash of the report, proving that at the time of making the solvency report, Coinfloor held all of our clients’ XBT funds. You can verify the amount and details of the transaction on the blockchain.

Key Pieces of information:


Provable Solvency Report #40 (July 28, 2017):
https://s3-eu-west-1.amazonaws.com/provablesolvency/solvency_20170728.txt

SHA-256 Hash of the Provable Solvency Report: 20170728514ca4d6cb04287fc3c1db0e5517ca086a2c395f0c34fad8677f7cf7b43933c6

Transaction ID: 27d73ad80ad69dd74e388f18f60dac03f327a79daef07c5afbeb8443bed71968

View the transaction here:
https://www.blocktrail.com/BTC/tx/27d73ad80ad69dd74e388f18f60dac03f327a79daef07c5afbeb8443bed71968

Your API authentication cookie:
You will find it in My Account > Dashboard in the Coinfloor signed in view, in the API section (visible only for fully verified accounts).

Where is my cookie?!

Instructions for Validating Solvency Report:

      1. Open the Provable Solvency Report file:

https://s3-eu-west-1.amazonaws.com/provablesolvency/solvency_20170728.txt

      2. Go to

http://www.xorbin.com/tools/sha256-hash-calculator or to your SHA256sum calculating application.

      Copy the entire contents of the solvency report into the SHA-256 generator and calculate the SHA-256 hash of the report.
      3. Go to

https://www.blocktrail.com/BTC/tx/27d73ad80ad69dd74e388f18f60dac03f327a79daef07c5afbeb8443bed71968

      At the bottom of the page, in the Output Scripts section, you will find the generated hash in the OP_RETURN output script of the transaction that includes all customer bitcoins.
      4. Go to

your local SHA1sum application

      to calculate the SHA-1 digest of a message consisting of the timestamp shown at the top of the Solvency Report (1498749879) and your API authentication cookie.
      Example (Linux):
                timestamp: 1501241504
                API authentication cookie (API Key): 9BTa7M0Z/Mrk6tFMJwEkTV3BQek=
                command: echo -n ‘15012415049BTa7M0Z/Mrk6tFMJwEkTV3BQek=’ | sha1sum
      5. Find the resulting hash in the solvency report. Your balance is shown on that line in satoshi units. 1 bitcoin = 100 000 000 satoshis. For your convenience, here is a link to a bitcoin unit converter:

http://www.satoshi.24ex.com

We believe that this approach is the best way to achieve maximum accountability while retaining privacy for our clients. We welcome your feedback and hope that in time, other exchanges will also help safeguard client funds by providing proof of solvency reports to their users on regular basis.

Thank you for your trust,

Coinfloor Team