Presentation I gave at BRIGHTTALK webinar in the BLOCKCHAIN SUMMIT on 10th Oct 2017.Covers technical overview of the concept and take off essentials for Bitcoin crime investigators.Details at https://www.brighttalk.com/webcast/1570/272431/bitcoin-forensics

1. But Keep Calm & Trust Forensics
By : ANUPAM TIWARI
EMAIL: anupamtiwari@protonmail.com

2. The views expressed in this
presentation are My OWN.
Reference to any specific
products, process ,or service do
not constitute or imply
endorsement, recommendation,
or views of any Govt
All images used are for illustrative
purposes only & Do not
promote any specific product

3. This PRESENTATION is not going to
make anyone of you a
BITCOIN FORENSIC EXPERT
INVESTIGATOR
BUT may only LEND you few TERMS
OF REFERENCES to build upon and
EXPLORE further

15. Name used by the
unknown person who
designed BITCOIN
and created its
original reference
implementation
SATOSHI
NAKAMOTO
Where did He GO?

17. 4356 $
SOURCE : https://blockchain.info/charts/n-transactions

18. 2 6 0 4 3 7
SOURCE : https://blockchain.info/charts/n-transactions

23. ANONYMITY
VS
PSEUDONYMITY
Mark TwainSamuel Clemens
public key addresses similar in function to an
email address, are used to send and receive
Bitcoins and record transactions, as opposed
to personally identifying information.

25. CRYPTOCURRENCY IS AN ATTEMPT
TO BRING BACK A DECENTRALISED
CURRENCY OF PEOPLE, ONE THAT IS NOT
SUBJECT TO INFLATIONARY MOVES BY
A CENTRAL BANK

29. More DETAILS a Forensic
Investigator KNOWS about the TECH
ARCHITECTURE, the CLOSER
he gets to CLOSE the CASE

32. BASICALLY CHUNKS OF INFO
THAT CAN BE USED TO
MATHEMATICAL
GUARANTEE ABOUT MESSAGES

35. Peer-to-
Peer (P2P)
network is
created when
two or
more PCs are
connected &
share
resources
without
going through a
separate
server
computer

36. MERKLE TREE

37. Distributed Ledger is a Consensus of
Replicated, Shared & Synchronized
digital data geographically spread across
multiple sites & countries

38. Type of Distributed Ledger, comprised
of Unchangeable, Digitally
Recorded Data in packages called
BLOCKS
TAMPER EVIDENT LEDGER

40. Linked list data structure, with
each block containing a
hash of the previous block

41. Proof Of Work Is A Piece Of Data
Which Is Difficult To Produce But
Easy For Others To Verify And Which
Satisfies Certain Requirements
Bitcoin Uses
The Hashcash Proof
Of Work System.
PROOF OF WORK

42. Each block is formed by a proof-of-
work algorithms, through which
consensus of this distributed
system could be obtained via the
longest possible chain

44. https://anders.com/blockchain/blockchain.html

45. Thus blockchain provides
the basis for the TRUSTLESS
DISTRIBUTED SYSTEM

47. A block is an aggregated set of data
Data is collected and
processed to fit in a
block through a
process called
MINING
Each block could be identified using
a Cryptographic Hash

48. Mining is the process
of writing pages
(blocks) of Bitcoin
transactions into the
‘The Bitcoin
Blockchain’, and
getting rewarded with
newly created bitcoins

49. Block will contain a hash
of the previous block, so
that blocks can form a
chain from the first block
ever (known as the
Genesis Block) to the
formed block

50. FIRST BLOCK : GENESIS

51. Every 10 minutes, all Bitcoin
transactions taking place are bundled
into a block
These blocks linked through a
timestamp signing, form a
chain (blockchain), which goes
back to the first block ever
created (mined)
The time stamping makes it
impossible to alter any part of it
once the network confirms it

52. These rules are inbuilt in the
Bitcoin core software, which
every node in the Bitcoin
network runs
Before a new block is added to the
blockchain, the Bitcoin network
has to reach a consensus on
based on predetermined rules

53. Data in a blockchain is
internally consistent
and immutable
Each block’s hash is
derived from the
contents of the block
Each block refers to
the previous block’s hash,
not a sequential number

54. THE LAST BITCOIN
(PROBABLY 21 MILLIONTH COIN)
WILL BE MINED IN THE YEAR
2140

56. Source : Alex Biryuk et al., Deanonymisation of Clients in Bitcoin P2P
Network
Bitcoin network is composed of
PEERS connected to others PEERS
over unencrypted TCP channels
Each peer attempts to
maintain EIGHT outgoing
connections to other peers
These eight peers are called
ENTRY NODES

57. Transaction and Block messages
are propagated in network by being
Relayed through these ENTRY NODES
to other peers
When X sends a transaction advertising
that he is transferring ownership of 1 BTC
to Y, his computer sends an inv message
to its immediate peers, the entry nodes

58. The inv message lets the entry
nodes know that there are
transactions or blocks
Entry nodes relay the data
farther throughout the network by
sending inv to their own peers
Entry nodes request full
transaction by sending
getdata response to X’s
computer

62. BITCOIN MINING

64. A reward system, in
the form of
a website or app, that
dispenses rewards in
the form of a satoshi,
for visitors to claim in
exchange for
completing
a captcha or task as
described by the
website.
SATOSHI : 1/100th of a Millionth BITCOIN

66. A user for CONDUCTING
TRANSACTIONS utilizing BITCOIN,
he or she must first DOWNLOAD and
setup a BITCOIN WALLET
BITCOIN WALLET can show the
total BALANCE of all BITCOINS it
CONTROLS and let A USER PAY a
specified AMOUNT

67. WALLET contains a USER’S
PRIVATE KEY, which ALLOWS
FOR THE SPENDING of the
BITCOINS, which are located in
the BLOCK CHAIN
Once wallet is INSTALLED &
CONFIGURED, an ADDRESS
is GENERATED which is
SIMILAR to an E-MAIL or
PHYSICAL ADDRESS

68. WALLET is basically
the Bitcoin Equivalent
of a Bank account.
Allows to RECEIVE BITCOINS,
them, and then
SEND them to others

69. Connected to the Internet
or is online is said to be HOT
Cold Wallets & Hot Wallets
Cold is considered
most Secure &
suitable for Storing
Large Amounts of
bitcoins
Hot is suitable for
Frequently
Accessed funds
COLD implies it is Offline or
Disconnected from the
Internet

70. Designedto be downloaded
& used on Laptops/PCs
DESKTOPWALLETS
Armory, Multibit, Msigna
and Hiveto mention a FEW
Easyto Access.
Available for Different OS
– Windows, Mac OS and Ubuntu.

71. MOBILEWALLETS

72. ONLINEWEBWALLETS

73. PHYSICALWALLETS
Once they are generated, you
print them out on a piece of
paper
Paper Wallets can
Securely hold your BITCOINS
in Cold Storage form for a
long time
Bitaddress.org
or Blockchain.info

74. BitcoinQt is the First ever built
bitcoin CLIENT WALLET
BITCOINCLIENTS
WALLETS
Original bitcoin
wallet used by the
Pioneers of the
currency
COMPUTERS installed with these wallets
FORM PART OF THE CORE
NETWORK & have access to all
transactions on the blockchain

75. HARDWAREWALLETS

78. BITCOIN ARTIFACTS

79. They DON’T EXIST
ANYWHERE, even
on a hard drive

80. When we say SOMEONE HAS
BITCOINS & you look at a
PARTICULAR BITCOIN ADDRESS,
there are NO DIGITAL BITCOINS held
AGAINST that ADDRESS
BALANCE of any BITCOIN
address ISN’T HELD at that
ADDRESS; one MUST
RECONSTRUCT it by looking at
the BLOCKCHAIN

81. Everyone on the NETWORK knows about a
TRANSACTION and THE HISTORY
OF A TRANSACTION can be TRACED
BACK to the point where the BITCOINS
were produced

82. Conduct a
SEARCH based
on BLOCK
NUMBER,
ADDRESS,
BLOCK HASH,
TRANSACTION
HASH or
PUBLIC KEY

84. SOURCE : https://blockchain.info/ip-log

88. LOCK FILE
DEBUG.LOG
PEERS.DAT
WALLET.DAT
BITCOIN-QT FOLDER STRUCTURE
DB LOCK FILE
EXTENSIVE LOGGING
FILE
PEER INFORMATION
STORAGE FOR
KEYS,TXN,METADATA
etc

90. BITCOIN-QT FOLDER STRUCTURE

91. BITCOIN-BLOCK FOLDER ANALYSIS

92. BITCOIN-QT FOLDER STRUCTURE
Blocks – This subdirectory contains
blockchain data and contains a
“blk.dat” file and a “blocks/index”
subdirectory
“blk.dat” stores actual Bitcoin
blocks dumped in raw format
The “blocks/index subdirectory” is a
database that contains metadata
about all known blocks

93. Chainstate subdirectory- it is a
database with a compact
representation of all currently unspent
transactions and some metadata about
where the transactions originated
BITCOIN-QT FOLDER STRUCTURE

94. Database subdirectory -
Contains database journaling
files
BITCOIN-QT FOLDER STRUCTURE

96. Number of
blocks preceding
particular block
on a block chain.
Genesis block has a height of zero
because zero block preceded it.

97. 20-byte hash formatted
using base58check to produce
either a P2PKH or P2SH
Bitcoin address
00000000001F1tAaz5x1HUXrCNLbtM*****

98. How difficult it is to find
a block relative to
the difficulty of finding the easiest
possible block. The easiest
possible block has a proof-of-
work difficulty of 1.
Difficulty is changed every
2016 blocks based on the time
it took to discover 2016
previous blocks.

100. 1.46 × 10^48 possible
Bitcoin Addresses
that gives every
person on Earth
2.05×10^38 Different
Addresses

102. Bitcoin Mixer is an Anonymous
Service, that confuses the trails
of Bitcoin transactions.

113. PROJECT TITANIUM : Main thrust of the European
Union’s Titanium Project is to Monitor blockchains,
deanonymize wallet addresses, surveil dark net
markets, and block terrorists and money launderers.
TITANIUM, which stands for Tools for the Investigation of
Transactions in Underground Markets

114. Private key of the suspect, they can
search for that particular key on the
Blockchain to Trace the purchases
to other potential Suspects.
investigator has the Bitcoin

115. Detecting such attackers is CHALLENGING
any day
Attacking Bitcoin via the Internet
infrastructure using routing attacks
As Bitcoin connections are routed over the
Internet—in clear text and without
integrity checks—any third-party can
eavesdrop, drop, modify, inject, or
delay Bitcoin messages

117. BITCOIN FORENSIC ARTIFACT EXAMINATION
Windows 7 Professional
Multibit
Bitcoin-Qt
Bitminter
Basic USB ASIC Bitcoin
Gateway laptop ML6720
120 GB WD hard drive
(4) USB ASIC Mining
drives
USB powered cooling fan
32 GB USB thumb drive

118. • System Info
• Info about Logged users
• Registry Info
• Remnants of Chats
• Web browsing Activities
• Recent Communications
• Info from Cloud Services
• Decryption Keys for encrypted
volumes mounted
COLLECTION OF BITCOIN ARTIFACTS

119. Utilizing the data from
344
transactions,
Meiklejohn able to
identify the owners of
more than a million
Bitcoin addresses
Sarah Meiklejohn, a Bitcoin focused
Computer Researcher
Extensive Research
in
Bitcoin Blockchain
Found that by looking
blockchain an
investigator can
uncover who owns a
Bitcoin addresses

120. 2015
“In this paper we show that combining TOR and
BITCOIN creates an ATTACK VECTOR for the
stealthy man-in-the-middle attacks. A LOW-
RESOURCE ATTACKER gain FULL
CONTROL of information flows between all users
who chose to use Bitcoin over TOR. In particular the
attacker CAN LINK TOGETHER USER’S
TRANSACTIONS regardless of pseudonyms used”

121. Bitcoin transactions occur via a
Network Connection, an investigator
should seize any Physical Object that
can connect to the Internet in addition
to the hard drive
COLLECTION OF BITCOIN ARTIFACTS

123. Ulbricht
Ross

126. anupamtiwari@protonmail.com
https://about.me/anupam.tiwari