1. What is Contract ?
2. What is Smart Contract
3. Why We need Smart Contract ?
4. How blockcain help us to build smart contract ?
5. How safe bockchain is?
6. Which all features are adopte from blockchain and what all problems are solved by it?
4. 4
Dubai - "Adopting Blockchain technology
Dubai stands to unlock 5.5 billion dirham
in savings annually in document
processing alone — equal to the one Burj
Khalifa’s worth of value every year."
Hero Motocorp – Vendor management
using Blockchain can reduce 80 % Cost
6. 6
If two people want to make a contract related to any thing they need trust each
other.
1. If they know each other trusting is easy
2. If they don’t know each other but physically present in front of each other
that may still do the job.
3. But if they don’t know each other and only connected virtually then trusting
each other become a issue.
Should I trust
him with my
money
Should I sell my
property to him?
Problem
7. 7
As solutions a intermediator introduced, Like online shopping both trust
Amazon, Ebay, Flipkart. Same way for property we trust Gov. Want to buy a
home on lone, start trusting bank etc..
Happy Happy
Solution
8. 8
Problem 1
This Intermediator Bank, Shopping website, Government are run by Human, So there is chances of
Corruptions also.
Problem 2
When everyone started doing business or transaction through Intermediators, They started to keep
records about each client or customers. So all information are stored centralized.
So if you look back history attackers primary motive is always information. And if they get access of a
centralized server contain information it’s a lottery for them
10. 10
Problem 3
Privacy – When ever you do any activity online, either your ISP or The End point know about your
activity. That also store on centralized server for future use.
11. 11
Problem 4
Impersonation / Identity Theft –
1. If some use a stole identity
2. If someone deny after contract
Problem 5
Double Spending problem
12. 12
Problem 6
Countries boundaries – Our money, tax system, Law are country oriented. How you are going to
deal with problem related to you cross border trading? Which law or which tax system to follow?
13. 13
We look into
how Smart
Contract
helping us to
solve This
problems
Authentication
Nonrepudiation
Data Privacy
Confidentiality
Integrity
17. 17
A smart contract is a
computer protocol intended to
digitally facilitate, verify,
or enforce the negotiation or
performance of a contract.
Smart contracts allow the
performance of credible
transactions without third
parties
What is Smart contract ?
18. 18
Smart Contract – Blockchain Implementation
A list of predefine condition, if meet the condition then it will execute
and no 3rd party require
IF
IF
IF
IF
IF
IF
29. 29
Blockchain
Satoshi Nakamoto
He introduced blockchain network, A decentralized P2P network. He published paper on bitcoin, helping people
share some value over network without any intermediators.
2008
31. 31
Blockchain
In layman term Blockchain is a number of block contain some
information and mathematically link with each other.
Now we will look into
1. What information one block contain
2. How they link with each other.
32. 32
1. Data
Blockchain
1. What information one block contain
Contract between A & B (Digital)
+
Both of their Digital Signature
And verified by “IF” condition
36. 36
1. Data
Blockchain
1. What information one block contain
2. Time Stamp
This Photo by Unknown Author is licensed
under CC BY
37. 37
1. Data
Blockchain
1. What information one block contain
2. Time Stamp
3. Every block store hash value of data with time stamp, as we know hash are use for data integrity.
Here every data are bind with timestamp so not only if data manipulated hash will change, if time
change by even by one second the hash will change also . This will avoid hash collision and provide
more data security
3. Hash (Data + Time Stamp)
LETTERS HASH
Paladion 1839de10415111d4ccf12e9f4787a053b320490b7d80b5ea0152d4c4cb5cab78
PALADION 9ca9837d549b6914ca6cc6dad790bff40b72248c6f12294ba95484061f5720cf
paladion 81e200925ec4fba1aff54e7cfb5d5fec292dba6cd9dbb4576505bf136d3ee6b2
38. 38
1. Data
Blockchain
1. What information one block contain
2. Time Stamp
4.
4. Will Discuss after point 5
3. Hash (Data + Time Stamp)
39. 39
1. Data
Blockchain
1. What information one block contain
2. Time Stamp
4.
5. Block Hash (1 + 2 + 3 + 4)
3. Hash (Data + Time Stamp)
5. If any change happen at 1,2,3 & 4 the hash of the
block will change. So that will protect this block from
manipulation
40. 40
Blockchain
2. How they link with each other.
Information – Genesis block
Previous block hash – 00000
Current Block Hash – XYZ22
Information – Smart Contract 1
Previous block hash – XYZ22
Current Block Hash – ABC57
Information –Smart Contract 2
Previous block hash – ABC57
Current Block Hash – FGD53
41. 41
Data Hash with time
stamp
P o i n t A
Current Block HashP o i n t B
Previous Block HashP o i n t C
Digital SignatureP o i n t D
Recap – Which all security features one
block have
44. 44
A
B
C
D
E
In This Network if one person create a block, Next step
he will do is broadcast the block towards everyone in
the same network
A
B
C
D
E
46. 46
Both Entity will generate their own Public & Private Key Pair using Cryptographic Algorithm
Each of them will use their public key as their identity in a network not there actual Name
Their Private key will act as their digital signature – So Contract will be sign with there
private key, and if need to verify public key will be use
Private key is always kept secure, and public key can be share with any one
Identity of every entity in blockchain are secure to maintain privacy
47. 47
Problem 1 – Intermediators Blockchain – Decentralized P2P Network
Problem 2 – Hacker & Data
Manipulation
Hash & Encryption
Problem 3 & 4 – Privacy Instead of identity blockchain use public & Private key
Problem 5 – Identity Theft /
Impersonation
Digital Signature
Beginning of the slide we marked some problem – Let see how many of them are solved by Block chain
48. 48
Some time we don’t need to
Upgrade the technology, we
need to update ourselves first
49. 49
• Blockchain – 1991 (Stuart & Scott)
• Market Tree - 1992, Bayer, Haber and Stornetta
• Proof of Work – 1993 Cynthia Dwork and Moni Naor
• Hash SHA2 – 2004
• Public Key – 1976, Diffie and Martin Hellman
• RSA - 1977: Ronald Rivest, Adi Shamir and Len Adleman
• Digital Signature - 1999
2008 – Satoshi Nakamoto
50. 50
Any
Questions ?
Do question, even the
basics! You will be a
fool for once! If you
don't, you will be, for a
lifetime..”
― Himmilicious
51. 51
THANK YOU
0 0 6 S a q u i b @ g m a i l . c o m
MD Saquib Nasir Khan
Threat Hunting
Editor's Notes
Prerequisite –
Cryptography, Digital signature, Hash fanction
Dubai – 2021 - 2022
89 215 212
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Trust Issue - 1. know each other
2. Don’t know but in front of
3. Virtually
Shopping example
Problem 1 - Corruption (Russian fall & Zimbabwean 1 dollar ) bear story
Problem 2 - records in centralized server & Hacker
Online privacy
Problem4 - Identity theft, impersonation, non repudiation
Problem 5 - Double spending (Vending machine)
Country oriented money, law & tax system
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