- Bitcoin was started on October 31, 2008. Open-sourced Jan 3, 2009. Creator pseudonym Satoshi Nakamoto.
- Technically not first cryptocurrency, DigiCash came in 1990.
+
@@ -87,6 +117,9 @@
Scarce
+
+ Acceptable
Bitcoin was started in late 2008. Open-sourced January 2009.
+ Creator pseudonym Satoshi Nakamoto.
First decentralized virtual currency.
-
What is money?
+What is money?
+ +
Medium of exchange: portable, durable, fungible
Unit of account: divisible, fungible
Store of value: durable, scarce, fungible
+ One more property: acceptable
+
Next: things we've used as money
Shells
@@ -114,6 +147,9 @@
Scarce
+
+ Acceptable
@@ -144,10 +180,13 @@
Scarce
+
+ Acceptable
Scarce
+
+ Acceptable
-
@@ -196,14 +238,18 @@
- Jack
- 12
- Tim
+ 57
Dave
9
+
+ Jack
+ 12
+
George
40
@@ -248,6 +294,10 @@
9.7
+
+ 57.0
+
1.1
@@ -267,10 +317,14 @@
- 
- 
- 
-
@@ -287,25 +341,43 @@
- How do you fix this?
+
+ 
+
- 
+
- 
+
+ 
-
+
+
+
@@ -313,7 +385,46 @@
-
+
+
+
+
+
+
+
+
+
+
@@ -321,31 +432,11 @@
-
-
-
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+
diff --git a/styles/PPAP.jpg b/styles/PPAP.jpg
new file mode 100644
index 0000000..e1f0aaf
Binary files /dev/null and b/styles/PPAP.jpg differ
diff --git a/styles/blockchain.css b/styles/blockchain.css
index e3af1b9..b563adc 100644
--- a/styles/blockchain.css
+++ b/styles/blockchain.css
@@ -14,6 +14,14 @@
line-height: 1.2;
}
+.highlighted {
+ background-color: #FF0;
+ color: black;
+ display: inline-block;
+ padding: 0.125em 0.25em;
+ margin: 0.25em auto;
+}
+
table.yesnomaybe {
border: 0px solid transparent;
margin: auto 0.5rem auto auto;
@@ -21,7 +29,9 @@ table.yesnomaybe {
table.yesnomaybe .yes, table.yesnomaybe .no, table.yesnomaybe .maybe {
width: 1em;
- background-size: auto 80%;
+ padding: 0.1em;
+ background-clip: padding-box;
+ background-size: contain;
background-position: center;
background-repeat: no-repeat;
}
diff --git a/styles/byzantine-fresca.jpg b/styles/byzantine-fresca.jpg
new file mode 100644
index 0000000..b1972a5
Binary files /dev/null and b/styles/byzantine-fresca.jpg differ
diff --git a/styles/envelopes.jpg b/styles/envelopes.jpg
new file mode 100644
index 0000000..e7b0aa6
Binary files /dev/null and b/styles/envelopes.jpg differ
diff --git a/styles/main.css b/styles/main.css
index 7dc2232..63d87f9 100644
--- a/styles/main.css
+++ b/styles/main.css
@@ -415,6 +415,9 @@ section {
[janus-timeline='past'] {
transition: transform ease 0.5s, opacity ease 0.5s, visibility step-end 0.5s;
}
+section[janus-timeline='present'] [janus-timeline='past']:not([janus-past]) {
+ transition: transform ease 0.5s, opacity ease 0.5s;
+}
[janus-timeline='present'] {
transition: transform ease 0.5s, opacity ease 0.5s, visibility step-start 0.5s;
- Gold (and silver).
+ Precious metals, gold and silver.
Pretty popular.
Still used today.
@@ -172,10 +211,13 @@
US dollars
- Used to represent gold and silver, after World War 1 pretty much everybody decided to switch to unbacked "floating money" so they could fuel government expenses with inflation.
+ Cash
+ Used to represent gold and silver, after World War 2 pretty much everybody decided to switch to unbacked "floating money" so they could fuel government expenses with inflation.
- 15
+ 15
+ 15
333BCBA13A54C8DCFD9B98C72B8DBDA78D8BEF2
-
-
- There's a company that actually did this, called DigiCash. they maintained a ledger with cryptographically controlled balances. Consumers weren't concerned enough about security or privacy and they ran out of money.
+
+ There's a company that actually did this, called DigiCash. they maintained a ledger with cryptographically controlled balances. Consumers weren't concerned enough about security or privacy and they ran out of money.
+
+ Money that depends on a centralized provider can be fragile since there's a single point of failure.
Real world, double spending is easy.
Two checks
First deposit "wins"
- All about timing
+ All about timing
+
+ the
+Byzantine Generals’
+problem
+The Byzantine army is divided into groups, each group led by a general. But some of the generals are traitors. How can the loyal generals share one plan of attack, even in the presence of a small group of traitors?
+
+ This kind of "antifragile" consensus they are looking for is called "Byzantine consensus".
Hashes
+Hashing is a one-way transformation of some arbitrary data into some random-seeming but bounded output.
+ We can get Byzantine consensus with creative use of hashes.
Proof of Work
+
+ Proof of Work
+In 1997 this guy Adam Back came up with HashCash. The idea is that an email client would brute-force a certain amount of zeros as the output to a cryptographic hashing algorithm.
+
+ Hash Pointers
- Hash Pointers
+Good data structure for a log is a linked list. Blocks with lists of transactions, and each one points to the previous block. But we want this log to be tamper-proof.
+ Hash pointers can make it so that changes earlier in the chain affect every item after that.
+ Currency
+Money
+| Durable | + |
|---|---|
| Portable | + |
| Divisible | + |
| Fungible | + |
| Scarce | + |
| Acceptable | + |
Identity
+
+ payment information
+ usernames
+ DNS
+
+ Proof of Existence
+
+ embedding a hash in the blockchain demonstrates an item's existence at point in the past
+
- payment information
- usernames
- DNS
-
- Identity
-
- embedding a hash in the blockchain demonstrates an item's existence at point in the past
-
- Proof of Existence
-Payment Infrastructure
-Smart Contracts
DAO
Ethereum/RootStock
-