init

48 files changed, 309 insertions, 0 deletions

diff --git a/SI/Resource/Blockchain & Cryptography/02_intro_to_cryptography.pdf b/SI/Resource/Blockchain & Cryptography/02_intro_to_cryptography.pdf
new file mode 100644
index 0000000..04639ee
--- /dev/null
+++ b/SI/Resource/Blockchain & Cryptography/02_intro_to_cryptography.pdf
diff --git a/SI/Resource/Blockchain & Cryptography/03_chaumian_ecash.pdf b/SI/Resource/Blockchain & Cryptography/03_chaumian_ecash.pdf
new file mode 100644
index 0000000..a55def3
--- /dev/null
+++ b/SI/Resource/Blockchain & Cryptography/03_chaumian_ecash.pdf
diff --git a/SI/Resource/Blockchain & Cryptography/04_bitcoin_public_ledger.pdf b/SI/Resource/Blockchain & Cryptography/04_bitcoin_public_ledger.pdf
new file mode 100644
index 0000000..45e2736
--- /dev/null
+++ b/SI/Resource/Blockchain & Cryptography/04_bitcoin_public_ledger.pdf
diff --git a/SI/Resource/Blockchain & Cryptography/05_blockchain_and_consensus_by_POW.pdf b/SI/Resource/Blockchain & Cryptography/05_blockchain_and_consensus_by_POW.pdf
new file mode 100644
index 0000000..79f8c70
--- /dev/null
+++ b/SI/Resource/Blockchain & Cryptography/05_blockchain_and_consensus_by_POW.pdf
diff --git a/SI/Resource/Blockchain & Cryptography/06_bitcoin_scripts.pdf b/SI/Resource/Blockchain & Cryptography/06_bitcoin_scripts.pdf
new file mode 100644
index 0000000..8a4ee3a
--- /dev/null
+++ b/SI/Resource/Blockchain & Cryptography/06_bitcoin_scripts.pdf
diff --git a/SI/Resource/Blockchain & Cryptography/Midterm Review - CS646.md b/SI/Resource/Blockchain & Cryptography/Midterm Review - CS646.md
new file mode 100644
index 0000000..5658631
--- /dev/null
+++ b/SI/Resource/Blockchain & Cryptography/Midterm Review - CS646.md
@@ -0,0 +1,309 @@
+---
+id: Midterm Review - CS646
+aliases:
+  - Guideline
+tags: []
+---
+
+# Guideline
+
+- ProctorU
+- 10-15 questions
+
+## History of money
+
+- Historical definition of money
+  - A medium of exchange
+  - A store of value
+  - A unit of account
+- Monetary system: is protocols for controlling the supply of money
+  - Money, payment system, monetary policy
+  - banking/financial system
+- Commodity vs fiat money
+  - Commodity:
+    - Commodity money derives its value from the commodity out of which it is
+      made. Its value is determined by the value of the material from which it
+      is crafted.
+    - Pros: **Intrinsic Value**, **Limited Supply**
+    - Cons: **Weight and Portability**, **Storage and Security**, **Dependence
+      on Commodity Value**
+  - Fiat:
+    - Fiat money doesn’t have intrinsic value; instead, it derives its value
+      from a government decree. It is not backed by a physical commodity but is
+      established as money by government regulation or law.
+    - Pros: **Lightweight and Portable**, **Flexible Monetary Policy**, **Not
+      Tied to Commodity Fluctuations**
+    - Cons: **No Intrinsic Value**, **Inflation Risk**
+- M1 vs M2
+  - M1: is the most liquid measure of the money supply and includes assets that
+    are directly suitable for transactions.
+    - **Components**:
+      1. **Currency in circulation**: This includes all coins and paper money
+         that are in the hands of the public, not held by the government, banks,
+         or other financial institutions.
+      2. **Demand deposits**: These are checking accounts or other types of bank
+         accounts from which deposited funds can be quickly withdrawn without
+         any restrictions.
+      3. **Traveler's checks**: Although their use has diminished significantly
+         with the rise of digital payment methods, traveler's checks are
+         traditionally a part of M1.
+      4. **Other checkable deposits (OCDs)**: This can include accounts like
+         Negotiable Order of Withdrawal (NOW) accounts.
+  - M2: includes all components of M1 plus near-money assets, which are
+    financial assets that can easily be converted into cash or are already in a
+    form that can be used for spending.
+    - **Components**:
+      1. **All components of M1**: Currency in circulation, demand deposits,
+         traveler's checks, and other checkable deposits.
+      2. **Savings accounts**: These accounts, including money market deposit
+         accounts, generally allow consumers to earn interest on their deposits,
+         but they might have some limitations on the number of transactions per
+         month.
+      3. **Time deposits**: This includes Certificates of Deposit (CDs) with a
+         value under $100,000. CDs are deposit accounts with a specific maturity
+         date and typically pay higher interest than regular savings accounts.
+      4. **Money market mutual funds (retail)**: These are funds that typically
+         invest in short-term debt securities and offer a return to their
+         holders. They're relatively liquid and can be quickly converted to
+         cash, though they are not as liquid as checking or savings accounts.
+
+## Intro to Crypto
+
+- 1-way hash (properties, attacks): is a mathematical algorithm that takes an
+  input (or 'message') and produces a fixed-size string of bytes, typically a
+  digest.
+  - Properties:
+    - One-wayness: Given an output, it is infeasible for any one to find an
+      input document which is hashed to that specific output
+    - Collision resistance: it is infeasible for any one to find two or more
+      input documents which are hashed to the same condensed output
+      - Type 1:
+        - An attacker has one input document in hands
+        - He attempts to find a different input document that is hashed to the
+          same output as is the first input
+      - Type 2:
+        - An attack is not given any specific input document
+        - His goal is find a pair of different input documents that are hashed
+          to the same output
+      - A good 1-way hash should be immune to both types of attacks
+  - Attacks:
+    - Brute force attack:
+      - Taking advantage of “birthday paradox”
+      - This is a long route, or the worst case scenario from an attacker’s
+        point of view, but the best case scenario from the designer’s point of
+        view
+    - Attacks using short cuts:
+      - Identifying inherent weaknesses of a 1-way hashing
+      - The nightmare scenario from a designer’s point of view
+    - Birthday Attack:
+      - Based on the birthday paradox, in a set of randomly generated hash
+        outputs, there's a good chance that two of them will be the same.
+      - The expected # of messages to be hashed before a coincidence/collision
+        occurs is $1.25 * 2^{t/2}$
+- Public key encryption: is a cryptographic system that uses two keys: a public
+  key, which is shared openly, and a private key, which remains confidential to
+  the owner
+  - RSA Public key encryption
+    - Key Generation:
+      1. $n=p×q \quad n,p \; prime$
+      2. $\varphi(n)=(p−1)(q−1)$
+      3. $1<e<\varphi(n)$ and $gcd(e,\varphi(n))=1$
+      4. $e * d \equiv 1*mod(\varphi(n))$
+      5. The _public key_ is $(e,n)$, and the _private key_ is $(d,n)$.
+    - Encryption:
+      - $c = m^e \;(mod\,N)$
+    - Decryption:
+      - $m = c^d \;(mod\,N)$
+- Digital signature
+  - DSS : A US government standard for digital signatures. It includes
+    specifications for the DSA (Digital Signature Algorithm).
+    - Public Key = $(y,p,q,g)$
+      - $p$ = a prime of at least 2048 bits.
+      - $q$ = a 160-bit prime divisor of $p - 1$.
+      - $g = h^{(p-1)/q}\;mod\;p$, where _h_ is any integer with $1 < h < p - 1$
+        s.t. $h^{(p-1)/q}\;mod\; p > 1$. That is _g_ has order $q\;mod\;p$.
+      - $y = g^x \;mod\;p$, where _x_ is an integer randomly selected from $[1,
+        q - 1]$
+    - Private Key = $x$
+    - Relationship: $y = g^x \;mod\;p$, $\;0 < x < q$
+    - Signing a document m
+      - Pick at random 𝒌 from $[1, q - 1]$.
+      - $r$ = $(g^k \;mod\;p)\;mod\;q$
+      - $s = (k^{-1} ∗ (HASH(m) + x ∗ r)) \;mod\;q$, where HASH is a 1-way hash
+        whose output is 160 bits
+      - Signature on $m$ = $(r,s)$
+    - Verification:
+      - Fetch Alice’s public key $(y,p,q,g)$ from the public key file
+      - $w = s^{-1} \;mod\;q$
+      - $a = HASH(m) * w \;mod \;q$
+      - $b = r*w \;mod\;q$
+      - $v = (g^a*y^b \;mod\;p)\;mod\;q$
+      - OK only if $v = r$
+    - **When 𝒑 is large (say ~700 digits), the best known algorithm for the
+      _Discrete-Logarithm Problem_ takes an _infeasible_ amount of time (the
+      problem is computationally infeasible).**
+  - ECDSA: A variant of the Digital Signature Algorithm (DSA) that uses elliptic
+    curve cryptography.
+    - ![[CleanShot 2023-10-05 at 10.03.23 1.png]]
+    - ![[CleanShot 2023-10-05 at 10.03.34 1.png]]
+    - ![[CleanShot 2023-10-05 at 10.03.45 1.png]]
+  - Schnorr:
+    - ![[CleanShot 2023-10-05 at 09.39.10.png]]
+    - ![[CleanShot 2023-10-05 at 09.40.10.png]]
+  - EC-Schnorr
+    - ![[CleanShot 2023-10-05 at 10.13.48.png]]
+    - EC-Schnorr is better than Schnorr
+      - Admit
+        - Security proofs
+        - Easy to implement threshold signature
+        - Blind signature
+      - Free of signature malleability
+      - Cleaner and slightly faster: Shorter Key and Signature Lengths
+- Malleability of ECDSA
+  - ![[CleanShot 2023-10-05 at 10.12.51.png]]
+- Multi-signature
+  - Schnorr multi-signature
+    - ![[CleanShot 2023-10-05 at 09.47.37.png]]
+    - ![[CleanShot 2023-10-05 at 09.47.51.png]]
+    - ![[CleanShot 2023-10-05 at 09.49.08.png]]
+    - ![[CleanShot 2023-10-05 at 09.50.45.png]]
+    - ![[CleanShot 2023-10-05 at 09.51.01.png]]
+    - ![[CleanShot 2023-10-05 at 09.56.20.png]]
+    - ![[CleanShot 2023-10-05 at 09.56.52.png]]
+    - ![[CleanShot 2023-10-05 at 09.57.08.png]]
+  - EC Schnorr multi-signature
+    - ![[CleanShot 2023-10-05 at 10.19.29.png]]
+    - ![[CleanShot 2023-10-05 at 10.19.34.png]]
+    - ![[CleanShot 2023-10-05 at 10.19.54.png]]
+    - ![[CleanShot 2023-10-05 at 10.20.04.png]]
+    - ![[CleanShot 2023-10-05 at 10.20.12.png]]
+    - ![[CleanShot 2023-10-05 at 10.22.39.png]]
+    - ![[CleanShot 2023-10-05 at 10.22.48.png]]
+    - ![[CleanShot 2023-10-05 at 10.22.54.png]]
+
+## Chaumian cash
+
+- 3-party model
+  - Bank: Withdraw (creation of cash) to Customer
+  - Customer: Payment to Shop
+  - Shop: Deposit (end of life of cash) to Bank
+  - ![[CleanShot 2023-10-05 at 10.29.17.png]]
+  - ![[CleanShot 2023-10-05 at 10.29.24.png]]
+- RSA blind signature
+  - ![[CleanShot 2023-10-05 at 10.34.02.png]]
+  - ![[CleanShot 2023-10-05 at 10.34.08.png]]
+  - ![[CleanShot 2023-10-05 at 10.34.16.png]]
+- Public and private keys used in Chaumian
+  - ![[CleanShot 2023-10-05 at 10.38.05.png]]
+- "Cut and choose" technique
+  - ![[CleanShot 2023-10-05 at 10.55.34.png]]
+- Detection of double spending
+  - Hiding ID in a coin: Force the customer to embed her ID/account # into
+    coins, using secret sharing technique
+    - Choose s and t such that $ID = s\bigoplus t$
+  - ![[CleanShot 2023-10-05 at 11.14.47.png]]
+  - ![[CleanShot 2023-10-05 at 11.14.52.png]]
+- Withdrawal
+  - ![[CleanShot 2023-10-05 at 11.20.12.png]]
+- Payment
+  - ![[CleanShot 2023-10-05 at 11.22.12.png]]
+- Deposit protocols
+  - ![[CleanShot 2023-10-05 at 11.24.06.png]]
+
+## Public Ledger
+
+- Blockchain
+- Transactions
+  - Key components of a TX
+  - TX ID
+- Examples of TXs
+- Bitcoin network
+  - Centralized
+  - Decentralized
+  - Distributed
+- How to explain Bitcoin to your grandma?
+  - Bitcoin is a decentralized digital currency, without a central bank or
+    single administrator, that can be sent from user to user on the peer-to-peer
+    bitcoin network without the need for intermediaries. Transactions are
+    verified by network nodes through cryptography and recorded in a public
+    distributed ledger called a blockchain
+
+## Consensus through proof of work
+
+- Merkle hash tree: is a data structure used in computer science and
+  cryptography. It is a tree in which every leaf node is labelled with the
+  cryptographic hash of a data block, and every non-leaf node is labelled with
+  the cryptographic hash of the labels of its child nodes. This hierarchical
+  structure provides an efficient way to verify data and is commonly used in
+  blockchain systems and peer-to-peer networks.
+  - Pros:
+    - Easy to detect modification to TXs
+    - Easy to prove inclusion or membership of TX
+    - Enhanced privacy
+- Block header (80 bytes)
+  - Version
+  - Hash of previous block
+  - Merkle root
+  - Time
+  - Target threshold
+  - None
+- Hash puzzle for mining/proof of work
+  - Target, difficulty, hashrate etc
+- ## Coinbase: is to create new bitcoin by a miner
+- Thwarting double spending:
+  - TXs are public & broadcast globally
+  - Miners always **extend the longest chain** when forking occurs
+    - **Block** in a shorter branch will eventually become. **orphaned** & be
+      abandoned
+    - Some TXs in the orphaned blocks **become unconfirmed**; will be picked up
+      by miners for confirmation in the longest chain
+- Distributed mining
+- Pooled mining
+  - Why:
+    - Due to the increased level of difficulty, mining individually using home
+      computers has become ineffective
+    - Pooling together computing power increases chances of success
+  - How
+    - Divide-and-Conquer
+      - Cut-up the space of nonces into sub-spaces
+      - search for the right nonce in a distributed manner
+
+## Bitcoin scripts
+
+- 2 parts of a script
+  - Public key script (scriptPubKey) in an unspent TX output (UTXO) received in
+    the past
+    - Akin to 1-time "Account #"
+    - Set conditions for ownership
+    - Locking UTXO to owner
+  - Signature script (scriptSig) in an input of a current TX when spending
+    - Proof of ownership
+    - Ensuring integrity of TX
+    - Unlocking UTXO by owner
+- 3 types of addresses
+  - Pay to Public Key Hash (P2PKH): _most popular_
+    - Alice the recipient prepares a public-private key pair. She gives the hash
+      value of her public key to a sender as an address to receive funds.
+  - Pay to Public Key (P2PK): _natural but an address could be longer than
+    P2PKH_
+    - Alice the recipient prepares a public- private key pair. She gives her
+      public key to a sender as an address to receive funds
+  - Pay to Script Hash (P2SH) Towards programmable cash: _most powerful, make
+    "programmable cash" possible_
+    - Alice the recipient prepares the script. She gives its hash value to a
+      sender as an address to receive funds.
+- How a script is executed (stack, left to right, push & pop)
+  - Script is stack based, forth-like, and written in "reverse Polish notation"
+  - Scan from left to right
+  - If it's data, push it onto the stack
+  - If it's an operator, pop one or more items off the stack, operate on them
+    and push the result back into the stack
+  - ![[CleanShot 2023-10-05 at 19.17.13@2x.png]]
+- Scripts for threshold multi signature
+  - ??
+- Common Bitcoin Opcodes/Commands:
+  - OP_DUP, OP_HASH160, OP_EQUALVERIFY, OP_CHECKSIG,
+    - ![[CleanShot 2023-10-05 at 19.30.19@2x.png]]
+  - OP_2 - OP_16:
+    - ![[CleanShot 2023-10-05 at 19.28.57@2x.png]]
+  - OP_CHECKMULTISIG, OP_EQUAL
diff --git a/SI/Resource/Blockchain & Cryptography/Screenshots/CleanShot 2023-10-05 at 09.39.10.png b/SI/Resource/Blockchain & Cryptography/Screenshots/CleanShot 2023-10-05 at 09.39.10.png
new file mode 100644
index 0000000..7b8ad90
--- /dev/null
+++ b/SI/Resource/Blockchain & Cryptography/Screenshots/CleanShot 2023-10-05 at 09.39.10.png
diff --git a/SI/Resource/Blockchain & Cryptography/Screenshots/CleanShot 2023-10-05 at 09.40.10.png b/SI/Resource/Blockchain & Cryptography/Screenshots/CleanShot 2023-10-05 at 09.40.10.png
new file mode 100644
index 0000000..6c21655
--- /dev/null
+++ b/SI/Resource/Blockchain & Cryptography/Screenshots/CleanShot 2023-10-05 at 09.40.10.png
diff --git a/SI/Resource/Blockchain & Cryptography/Screenshots/CleanShot 2023-10-05 at 09.47.37.png b/SI/Resource/Blockchain & Cryptography/Screenshots/CleanShot 2023-10-05 at 09.47.37.png
new file mode 100644
index 0000000..6341f11
--- /dev/null
+++ b/SI/Resource/Blockchain & Cryptography/Screenshots/CleanShot 2023-10-05 at 09.47.37.png
diff --git a/SI/Resource/Blockchain & Cryptography/Screenshots/CleanShot 2023-10-05 at 09.47.51.png b/SI/Resource/Blockchain & Cryptography/Screenshots/CleanShot 2023-10-05 at 09.47.51.png
new file mode 100644
index 0000000..8e313b5
--- /dev/null
+++ b/SI/Resource/Blockchain & Cryptography/Screenshots/CleanShot 2023-10-05 at 09.47.51.png
diff --git a/SI/Resource/Blockchain & Cryptography/Screenshots/CleanShot 2023-10-05 at 09.49.08.png b/SI/Resource/Blockchain & Cryptography/Screenshots/CleanShot 2023-10-05 at 09.49.08.png
new file mode 100644
index 0000000..bd13ce7
--- /dev/null
+++ b/SI/Resource/Blockchain & Cryptography/Screenshots/CleanShot 2023-10-05 at 09.49.08.png
diff --git a/SI/Resource/Blockchain & Cryptography/Screenshots/CleanShot 2023-10-05 at 09.50.45.png b/SI/Resource/Blockchain & Cryptography/Screenshots/CleanShot 2023-10-05 at 09.50.45.png
new file mode 100644
index 0000000..58276b8
--- /dev/null
+++ b/SI/Resource/Blockchain & Cryptography/Screenshots/CleanShot 2023-10-05 at 09.50.45.png
diff --git a/SI/Resource/Blockchain & Cryptography/Screenshots/CleanShot 2023-10-05 at 09.51.01.png b/SI/Resource/Blockchain & Cryptography/Screenshots/CleanShot 2023-10-05 at 09.51.01.png
new file mode 100644
index 0000000..21b60b5
--- /dev/null
+++ b/SI/Resource/Blockchain & Cryptography/Screenshots/CleanShot 2023-10-05 at 09.51.01.png
diff --git a/SI/Resource/Blockchain & Cryptography/Screenshots/CleanShot 2023-10-05 at 09.56.20.png b/SI/Resource/Blockchain & Cryptography/Screenshots/CleanShot 2023-10-05 at 09.56.20.png
new file mode 100644
index 0000000..9a46c81
--- /dev/null
+++ b/SI/Resource/Blockchain & Cryptography/Screenshots/CleanShot 2023-10-05 at 09.56.20.png
diff --git a/SI/Resource/Blockchain & Cryptography/Screenshots/CleanShot 2023-10-05 at 09.56.52.png b/SI/Resource/Blockchain & Cryptography/Screenshots/CleanShot 2023-10-05 at 09.56.52.png
new file mode 100644
index 0000000..fbfab60
--- /dev/null
+++ b/SI/Resource/Blockchain & Cryptography/Screenshots/CleanShot 2023-10-05 at 09.56.52.png
diff --git a/SI/Resource/Blockchain & Cryptography/Screenshots/CleanShot 2023-10-05 at 09.57.08.png b/SI/Resource/Blockchain & Cryptography/Screenshots/CleanShot 2023-10-05 at 09.57.08.png
new file mode 100644
index 0000000..433b392
--- /dev/null
+++ b/SI/Resource/Blockchain & Cryptography/Screenshots/CleanShot 2023-10-05 at 09.57.08.png
diff --git a/SI/Resource/Blockchain & Cryptography/Screenshots/CleanShot 2023-10-05 at 10.03.23 1.png b/SI/Resource/Blockchain & Cryptography/Screenshots/CleanShot 2023-10-05 at 10.03.23 1.png
new file mode 100644
index 0000000..25a5b58
--- /dev/null
+++ b/SI/Resource/Blockchain & Cryptography/Screenshots/CleanShot 2023-10-05 at 10.03.23 1.png
diff --git a/SI/Resource/Blockchain & Cryptography/Screenshots/CleanShot 2023-10-05 at 10.03.23.png b/SI/Resource/Blockchain & Cryptography/Screenshots/CleanShot 2023-10-05 at 10.03.23.png
new file mode 100644
index 0000000..25a5b58
--- /dev/null
+++ b/SI/Resource/Blockchain & Cryptography/Screenshots/CleanShot 2023-10-05 at 10.03.23.png
diff --git a/SI/Resource/Blockchain & Cryptography/Screenshots/CleanShot 2023-10-05 at 10.03.34 1.png b/SI/Resource/Blockchain & Cryptography/Screenshots/CleanShot 2023-10-05 at 10.03.34 1.png
new file mode 100644
index 0000000..c62d235
--- /dev/null
+++ b/SI/Resource/Blockchain & Cryptography/Screenshots/CleanShot 2023-10-05 at 10.03.34 1.png
diff --git a/SI/Resource/Blockchain & Cryptography/Screenshots/CleanShot 2023-10-05 at 10.03.34.png b/SI/Resource/Blockchain & Cryptography/Screenshots/CleanShot 2023-10-05 at 10.03.34.png
new file mode 100644
index 0000000..c62d235
--- /dev/null
+++ b/SI/Resource/Blockchain & Cryptography/Screenshots/CleanShot 2023-10-05 at 10.03.34.png
diff --git a/SI/Resource/Blockchain & Cryptography/Screenshots/CleanShot 2023-10-05 at 10.03.45 1.png b/SI/Resource/Blockchain & Cryptography/Screenshots/CleanShot 2023-10-05 at 10.03.45 1.png
new file mode 100644
index 0000000..8a53593
--- /dev/null
+++ b/SI/Resource/Blockchain & Cryptography/Screenshots/CleanShot 2023-10-05 at 10.03.45 1.png
diff --git a/SI/Resource/Blockchain & Cryptography/Screenshots/CleanShot 2023-10-05 at 10.03.45.png b/SI/Resource/Blockchain & Cryptography/Screenshots/CleanShot 2023-10-05 at 10.03.45.png
new file mode 100644
index 0000000..8a53593
--- /dev/null
+++ b/SI/Resource/Blockchain & Cryptography/Screenshots/CleanShot 2023-10-05 at 10.03.45.png
diff --git a/SI/Resource/Blockchain & Cryptography/Screenshots/CleanShot 2023-10-05 at 10.12.51.png b/SI/Resource/Blockchain & Cryptography/Screenshots/CleanShot 2023-10-05 at 10.12.51.png
new file mode 100644
index 0000000..bc5ed34
--- /dev/null
+++ b/SI/Resource/Blockchain & Cryptography/Screenshots/CleanShot 2023-10-05 at 10.12.51.png
diff --git a/SI/Resource/Blockchain & Cryptography/Screenshots/CleanShot 2023-10-05 at 10.13.48.png b/SI/Resource/Blockchain & Cryptography/Screenshots/CleanShot 2023-10-05 at 10.13.48.png
new file mode 100644
index 0000000..c48b228
--- /dev/null
+++ b/SI/Resource/Blockchain & Cryptography/Screenshots/CleanShot 2023-10-05 at 10.13.48.png
diff --git a/SI/Resource/Blockchain & Cryptography/Screenshots/CleanShot 2023-10-05 at 10.19.29.png b/SI/Resource/Blockchain & Cryptography/Screenshots/CleanShot 2023-10-05 at 10.19.29.png
new file mode 100644
index 0000000..3b4db81
--- /dev/null
+++ b/SI/Resource/Blockchain & Cryptography/Screenshots/CleanShot 2023-10-05 at 10.19.29.png
diff --git a/SI/Resource/Blockchain & Cryptography/Screenshots/CleanShot 2023-10-05 at 10.19.34.png b/SI/Resource/Blockchain & Cryptography/Screenshots/CleanShot 2023-10-05 at 10.19.34.png
new file mode 100644
index 0000000..a6ec2d8
--- /dev/null
+++ b/SI/Resource/Blockchain & Cryptography/Screenshots/CleanShot 2023-10-05 at 10.19.34.png
diff --git a/SI/Resource/Blockchain & Cryptography/Screenshots/CleanShot 2023-10-05 at 10.19.54.png b/SI/Resource/Blockchain & Cryptography/Screenshots/CleanShot 2023-10-05 at 10.19.54.png
new file mode 100644
index 0000000..d73ff00
--- /dev/null
+++ b/SI/Resource/Blockchain & Cryptography/Screenshots/CleanShot 2023-10-05 at 10.19.54.png
diff --git a/SI/Resource/Blockchain & Cryptography/Screenshots/CleanShot 2023-10-05 at 10.20.04.png b/SI/Resource/Blockchain & Cryptography/Screenshots/CleanShot 2023-10-05 at 10.20.04.png
new file mode 100644
index 0000000..2479351
--- /dev/null
+++ b/SI/Resource/Blockchain & Cryptography/Screenshots/CleanShot 2023-10-05 at 10.20.04.png
diff --git a/SI/Resource/Blockchain & Cryptography/Screenshots/CleanShot 2023-10-05 at 10.20.12.png b/SI/Resource/Blockchain & Cryptography/Screenshots/CleanShot 2023-10-05 at 10.20.12.png
new file mode 100644
index 0000000..b9ace18
--- /dev/null
+++ b/SI/Resource/Blockchain & Cryptography/Screenshots/CleanShot 2023-10-05 at 10.20.12.png
diff --git a/SI/Resource/Blockchain & Cryptography/Screenshots/CleanShot 2023-10-05 at 10.22.39.png b/SI/Resource/Blockchain & Cryptography/Screenshots/CleanShot 2023-10-05 at 10.22.39.png
new file mode 100644
index 0000000..3fdbe8b
--- /dev/null
+++ b/SI/Resource/Blockchain & Cryptography/Screenshots/CleanShot 2023-10-05 at 10.22.39.png
diff --git a/SI/Resource/Blockchain & Cryptography/Screenshots/CleanShot 2023-10-05 at 10.22.48.png b/SI/Resource/Blockchain & Cryptography/Screenshots/CleanShot 2023-10-05 at 10.22.48.png
new file mode 100644
index 0000000..9405e91
--- /dev/null
+++ b/SI/Resource/Blockchain & Cryptography/Screenshots/CleanShot 2023-10-05 at 10.22.48.png
diff --git a/SI/Resource/Blockchain & Cryptography/Screenshots/CleanShot 2023-10-05 at 10.22.54.png b/SI/Resource/Blockchain & Cryptography/Screenshots/CleanShot 2023-10-05 at 10.22.54.png
new file mode 100644
index 0000000..aa7a339
--- /dev/null
+++ b/SI/Resource/Blockchain & Cryptography/Screenshots/CleanShot 2023-10-05 at 10.22.54.png
diff --git a/SI/Resource/Blockchain & Cryptography/Screenshots/CleanShot 2023-10-05 at 10.29.17.png b/SI/Resource/Blockchain & Cryptography/Screenshots/CleanShot 2023-10-05 at 10.29.17.png
new file mode 100644
index 0000000..32c41b2
--- /dev/null
+++ b/SI/Resource/Blockchain & Cryptography/Screenshots/CleanShot 2023-10-05 at 10.29.17.png
diff --git a/SI/Resource/Blockchain & Cryptography/Screenshots/CleanShot 2023-10-05 at 10.29.24.png b/SI/Resource/Blockchain & Cryptography/Screenshots/CleanShot 2023-10-05 at 10.29.24.png
new file mode 100644
index 0000000..64a7037
--- /dev/null
+++ b/SI/Resource/Blockchain & Cryptography/Screenshots/CleanShot 2023-10-05 at 10.29.24.png
diff --git a/SI/Resource/Blockchain & Cryptography/Screenshots/CleanShot 2023-10-05 at 10.34.02.png b/SI/Resource/Blockchain & Cryptography/Screenshots/CleanShot 2023-10-05 at 10.34.02.png
new file mode 100644
index 0000000..4f947fb
--- /dev/null
+++ b/SI/Resource/Blockchain & Cryptography/Screenshots/CleanShot 2023-10-05 at 10.34.02.png
diff --git a/SI/Resource/Blockchain & Cryptography/Screenshots/CleanShot 2023-10-05 at 10.34.08.png b/SI/Resource/Blockchain & Cryptography/Screenshots/CleanShot 2023-10-05 at 10.34.08.png
new file mode 100644
index 0000000..f3d2f14
--- /dev/null
+++ b/SI/Resource/Blockchain & Cryptography/Screenshots/CleanShot 2023-10-05 at 10.34.08.png
diff --git a/SI/Resource/Blockchain & Cryptography/Screenshots/CleanShot 2023-10-05 at 10.34.16.png b/SI/Resource/Blockchain & Cryptography/Screenshots/CleanShot 2023-10-05 at 10.34.16.png
new file mode 100644
index 0000000..ba17e51
--- /dev/null
+++ b/SI/Resource/Blockchain & Cryptography/Screenshots/CleanShot 2023-10-05 at 10.34.16.png
diff --git a/SI/Resource/Blockchain & Cryptography/Screenshots/CleanShot 2023-10-05 at 10.38.05.png b/SI/Resource/Blockchain & Cryptography/Screenshots/CleanShot 2023-10-05 at 10.38.05.png
new file mode 100644
index 0000000..168703f
--- /dev/null
+++ b/SI/Resource/Blockchain & Cryptography/Screenshots/CleanShot 2023-10-05 at 10.38.05.png
diff --git a/SI/Resource/Blockchain & Cryptography/Screenshots/CleanShot 2023-10-05 at 10.55.34.png b/SI/Resource/Blockchain & Cryptography/Screenshots/CleanShot 2023-10-05 at 10.55.34.png
new file mode 100644
index 0000000..4d44a17
--- /dev/null
+++ b/SI/Resource/Blockchain & Cryptography/Screenshots/CleanShot 2023-10-05 at 10.55.34.png
diff --git a/SI/Resource/Blockchain & Cryptography/Screenshots/CleanShot 2023-10-05 at 11.14.47.png b/SI/Resource/Blockchain & Cryptography/Screenshots/CleanShot 2023-10-05 at 11.14.47.png
new file mode 100644
index 0000000..a25e008
--- /dev/null
+++ b/SI/Resource/Blockchain & Cryptography/Screenshots/CleanShot 2023-10-05 at 11.14.47.png
diff --git a/SI/Resource/Blockchain & Cryptography/Screenshots/CleanShot 2023-10-05 at 11.14.52.png b/SI/Resource/Blockchain & Cryptography/Screenshots/CleanShot 2023-10-05 at 11.14.52.png
new file mode 100644
index 0000000..a3b2fa2
--- /dev/null
+++ b/SI/Resource/Blockchain & Cryptography/Screenshots/CleanShot 2023-10-05 at 11.14.52.png
diff --git a/SI/Resource/Blockchain & Cryptography/Screenshots/CleanShot 2023-10-05 at 11.20.12.png b/SI/Resource/Blockchain & Cryptography/Screenshots/CleanShot 2023-10-05 at 11.20.12.png
new file mode 100644
index 0000000..f7f65dd
--- /dev/null
+++ b/SI/Resource/Blockchain & Cryptography/Screenshots/CleanShot 2023-10-05 at 11.20.12.png
diff --git a/SI/Resource/Blockchain & Cryptography/Screenshots/CleanShot 2023-10-05 at 11.22.12.png b/SI/Resource/Blockchain & Cryptography/Screenshots/CleanShot 2023-10-05 at 11.22.12.png
new file mode 100644
index 0000000..c9526b3
--- /dev/null
+++ b/SI/Resource/Blockchain & Cryptography/Screenshots/CleanShot 2023-10-05 at 11.22.12.png
diff --git a/SI/Resource/Blockchain & Cryptography/Screenshots/CleanShot 2023-10-05 at 11.24.06.png b/SI/Resource/Blockchain & Cryptography/Screenshots/CleanShot 2023-10-05 at 11.24.06.png
new file mode 100644
index 0000000..b7eabdf
--- /dev/null
+++ b/SI/Resource/Blockchain & Cryptography/Screenshots/CleanShot 2023-10-05 at 11.24.06.png
diff --git a/SI/Resource/Blockchain & Cryptography/Screenshots/CleanShot 2023-10-05 at 19.17.13@2x.png b/SI/Resource/Blockchain & Cryptography/Screenshots/CleanShot 2023-10-05 at 19.17.13@2x.png
new file mode 100644
index 0000000..1ed832c
--- /dev/null
+++ b/SI/Resource/Blockchain & Cryptography/Screenshots/CleanShot 2023-10-05 at 19.17.13@2x.png
diff --git a/SI/Resource/Blockchain & Cryptography/Screenshots/CleanShot 2023-10-05 at 19.26.10@2x.png b/SI/Resource/Blockchain & Cryptography/Screenshots/CleanShot 2023-10-05 at 19.26.10@2x.png
new file mode 100644
index 0000000..0bc2580
--- /dev/null
+++ b/SI/Resource/Blockchain & Cryptography/Screenshots/CleanShot 2023-10-05 at 19.26.10@2x.png
diff --git a/SI/Resource/Blockchain & Cryptography/Screenshots/CleanShot 2023-10-05 at 19.28.57@2x.png b/SI/Resource/Blockchain & Cryptography/Screenshots/CleanShot 2023-10-05 at 19.28.57@2x.png
new file mode 100644
index 0000000..9f08859
--- /dev/null
+++ b/SI/Resource/Blockchain & Cryptography/Screenshots/CleanShot 2023-10-05 at 19.28.57@2x.png
diff --git a/SI/Resource/Blockchain & Cryptography/Screenshots/CleanShot 2023-10-05 at 19.30.19@2x.png b/SI/Resource/Blockchain & Cryptography/Screenshots/CleanShot 2023-10-05 at 19.30.19@2x.png
new file mode 100644
index 0000000..1072f2f
--- /dev/null
+++ b/SI/Resource/Blockchain & Cryptography/Screenshots/CleanShot 2023-10-05 at 19.30.19@2x.png