The common base on which the entire structure and technique of the draws made on Pickaw rests.

Overview of the Drawchain™

Technical definitions

Before getting to the heart of the matter, here is a list of technical definitions to familiarize yourself with the terms you will encounter several times on this page:

• master_seed: a unique and random string of 32 characters in base62.
• seed_pool: finite list of hash generated consecutively.
• hash, global_hash, ending_hash: unique and random string of 64 hexadecimal characters.
• seed: unique and random string of 16 characters in base62.
• sha256: standardized and highly secure hash function.
• base62: coding the information in 62 characters.

Let's go into details...

It's time to get started! As described above, the Drawchain™ is a name given to the list of Seed Pools. So we'll see now what it contains and how the Seed Pools feed it!

Creation of a Seed Pool

The origin of a seed_pool comes from the master_seed generated by Random.org at our request each evening shortly before midnight UTC for the following day.

This master_seed is then used to generate a list of hash large enough to serve all draws over the lifetime of the seed_pool.

Here are the steps for generating the list of hash:

• 1. Hashing the master_seed with sha256 to create the hash #1
• 2. Hashing the hash #1 with sha256 to create the hash #2
• 3. Repeat step (2.) until you have a list of hash large enough

All hash are therefore generated consecutively and depend on the master_seed.

The ending_hash is the last hash generated, it is not used and only ensures that the seed_pool has a beginning (master_seed) and an end (ending_hash) in order to prove that it has not been altered during its lifetime.

Once all hash have been generated, the seed_pool is finally ready to be used. The previous one is disabled and the new one takes over; the previous master_seed is now public and can be checked (see below).

Generation and use of a Seed

When a draw is requested on Pickaw, a hash is removed from the top of the existing seed_pool and generates a unique seed that will be assigned and used for the draw.

Here are the steps for generating a seed:

• 1. The hash is converted to base 10 and then divided by the limit value of a seed (62¹⁶) to keep only the rest of the division (this operation is also called modulo)
• 2. The value obtained is converted into base62, prefixed by as many zeros as necessary to produce a string of 16 characters: we therefore obtain the seed

The generated seed is saved and can now be used to give rise to the draw... and so on until the seed_pool is taken out of service.

We can see on this representation that 4 seeds were generated (from the last hash of the seed_pool) until it was taken out of service. The other hash are unused and have not resulted in the creation of seed.

Verification of draws

Now that you know how seed_pool and seed are generated, we come to the interesting and interactive part: how we prove that the winners come from the fruits of chance. A coincidence that you can check for yourself!

The verification can be done from any level of the Drawchain™ and in several different ways that we list below.

From the master_seed

To begin with, you can check that the master_seed we use to generate the hash of a seed_pool is the one from Random.org using the link attached to the master_seed directly from Drawchain™ or the Seed Pool in question.

From the seed_pool

Also, you can check at any time that the list of hash generated has not been altered and follows the logic described above. To ensure this, we have created a JSFiddle available below to be able to reproduce our generation:

How to use it?

• 1. Enter a master_seed (or a hash of a seed_pool) in the "Start hash" field
• 2. Enter the ending_hash (or a subsequent hash) within the same seed_pool in the "End hash*" field
• 3. Click on the "Compute!" button

From the seed

Finally, the positions of the persons drawn can be checked at any time from the seed as soon as a draw is completed. To ensure this, we have created a JSFiddle available below to be able to reproduce the generation of positions:

How to use it?

• 1. Enter the seed of the draw in the "Seed of the draw" field
• 2. Enter the number of contest entries in the "Number of entries" field
• 3. Enter the number of winners to be drawn in the "Number of winners" field
• 4. Click on the "Compute!" button

There you go, now the Drawchain™ and its mechanism, which alone took several months of work, have no more secrets for you! We hope these explanations have been clear and have not lost you.