DASH SCHOOL BY AMANDA B. JOHNSON LESSON 3.0

Hello, and welcome back to Dash School, Padawan,
I am your teacher, Amanda B Johnson
and as a quick recap, what we've discussed thus far is
in our hypothetical digital ledger of e-Money
or hey, our blockchain,
the "who" gets to make updates to it
are the "miners".
You know, those people with the funny fancy
math problem solving computers.
A miner gets to make updates to the ledger
when their machine was the first one to have
solved the math problem.
This being done in a regular and orderly manner.
And the reason why we are able to trust these entries
into the ledger as being accurate is that the entire
history of every unit of e-Money is public in the blockchain.
Just as an example, imagine that this is a zoomed in
snapshot of two consecutive blocks.
If this block shows me having more units of e-Money
than I did in the last block, there has to be a transaction
a record of someone sending me that e-Money
for this block to be valid.
If there isn't...... Not a valid block.
Same would go for your balance.
If this block shows you as having zero
and in the last block, you had 2.5 units of e-Money,
again, there must, somewhere in this block, be a record
of a transaction of you sending your 2.5 units of e-Money
somewhere else. If that didn't actually happen,
invalid.
And so you may be wondering "How do people send units of
e-Money to one another - to then be recorded in these blocks
in the blockchain?"
And that takes us to what I told you today's lesson would be about.
Cryptography is a form of mathematics that provides the basis
for how different accounts on the blockchain interact with one another.
And you don't need to understand cryptography, trust me, I don't,
to understand how we use it.
Remember how I mentioned in the last lesson that
on a blockchain, our accounts aren't organized by something
like our name, But are rather tracked
by cryptographic, "alpha-numeric" addresses
that look something like this.
(Pst) The word alpha numeric being a combination of
alphabetic letters and numbers.
There you go.
So if you wanted to, say, pay me some units of e-Money
to pay me back for taking you out to lunch,
I would send you this alpha-numeric address
and that would be the address you would send the
units of e-Money to from your wallet.
So our blockchain would show something like
your address, unique from mine, having sent 3 units of e-Money
to my address.
And the next block would be published to reflect this transaction.
So that leaves us with the question, well, how did you make
that transaction? Did you give a phone call to
one of the miners and read them off your long alpha-numeric
address and read them off mine and say "Hey, make the update."?
No, what you did was; you broadcasted a message signed
by your private key.
(blah) - rewind-
Your address, (points) you know, the one where you
receive payments and then can send on payments to others?
there is another word for it. It can also be referred to as
your public address.
And guess what? The only way to move funds out of this
address, that is, the only way to "spend" from it,
is to know the private key.
And private keys are really long and look something like that (points)
And they're stored right within your wallet.
So it's not like you have to memorize them or something.
And so that's how payments on the e-Money ledger work.
You receive funds to your public address,
and you can only spend them, that is you can only move them
on the ledger if your wallet software contains the private key.
That makes private keys super top secret
because anybody who knows the private key for a public
address can spend from it.
That's why nobody goes around posting their private keys
in online forums. it's just not done.
So when using your hypothetical e-Money wallet
and you want to send Amanda 3 e-Moneys for covering
lunch yesterday, all you, as the user do, is tell your wallet
you want to send 3 e-Money and click send.
Easy enough.
What your wallet is doing however, is creating a signature
of your private key that only you know, that broadcasts
the amount you want to send and to whom
to the entire rest of the network.
so that they can update their ledgers accordingly.
So that whole public address, private key thing;
the stuff that's mostly managed by your wallet?
That's the cryptography bit.
See? I told you it wasn't that hard.
And as a little bonus bit of knowledge for you,
remember how mining is solving math problems?
The math that those mining machines are doing
are called hash functions. And they are based
on cryptography.
Cool, huh?
So, I have to say right now, congratulations to you
because thus far, you already know everything you
need to know about a blockchain.
First, that it's a digital ledger.
Second, that updates to it are mined,
And third, is that the account system, you know
the sending and receiving bit, as well as the mining system
is all based on a form of math called cryptography.
You win! You win the golden ticket for getting this far!
So that just leaves one question in my mind really.
If this blockchain system I've just described to you
makes for such a cool e-Money and all,
Why aren't you neighbors using a blockchain based
form of money?
Why doesn't the butcher down the street accept
some kind of e-Money?
How is it that this whole money by blockchain phenomena
has not spread across the face of the Earth?
Well, at Dash, Digital Cash, that's because we believe
that it's got to be way more functional than that.
So, what makes Dash different?
Why do we believe that Dash will become the e-money that
your neighbors and neighborhood butcher, and yes, even
"Mother" comes to use?
Simply tune into the next episode of Dash School
to find the answer.