webinar on bitcoin forensics : brighttalk

But Keep Calm & Trust Forensics

By : ANUPAM TIWARIEMAIL: [email protected]

The views expressed in thispresentation 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

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

Name used by the

unknown person who

designed BITCOIN

and created its

original reference

implementation

SATOSHI

NAKAMOTO

Where did He GO?

4356 $

SOURCE : https://blockchain.info/charts/n-transactions

2 6 0 4 3 7

SOURCE : https://blockchain.info/charts/n-transactions

ANONYMITY

VS

PSEUDONYMITYMark TwainSamuel Clemens

public key addresses similar in function to anemail address, are used to send and receiveBitcoins and record transactions, as opposedto personally identifying information.

CRYPTOCURRENCY IS AN ATTEMPTTO BRING BACK A DECENTRALISEDCURRENCY OF PEOPLE, ONE THAT IS NOTSUBJECT TO INFLATIONARY MOVES BY

A CENTRAL BANK

More DETAILS a Forensic Investigator KNOWS about the TECH ARCHITECTURE, the CLOSER

he gets to CLOSE the CASE

BASICALLY CHUNKS OF INFO

THAT CAN BE USED TO

MATHEMATICAL

GUARANTEE ABOUT MESSAGES

Peer-to-

Peer (P2P)

network is

created when

two or

more PCs are

connected &

share

resources

without

going through a

separate

server

computer

MERKLE TREE

Distributed Ledger is a Consensus of

Replicated, Shared & Synchronized

digital data geographically spread across

multiple sites & countries

Type of Distributed Ledger, comprised

of Unchangeable, Digitally

Recorded Data in packages called

BLOCKS

TAMPER EVIDENT LEDGER

Linked list data structure, with

each block containing a

hash of the previous block

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

https://en.bitcoin.it/wiki/Hashcash

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

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

Thus blockchain provides

the basis for the TRUSTLESS

DISTRIBUTED SYSTEM

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

Mining is the process

of writing pages

(blocks) of Bitcoin

transactions into the

‘The Bitcoin

Blockchain’, and

getting rewarded with

newly created bitcoins

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

FIRST BLOCK : GENESIS

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

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

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

THE LAST BITCOIN

(PROBABLY 21 MILLIONTH COIN)

WILL BE MINED IN THE YEAR

2140

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

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

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

BITCOIN MINING

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

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

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

WALLET is basically

the Bitcoin Equivalent

of a Bank account.

Allows to RECEIVE BITCOINS,

them, and then

SEND them to others

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

Designed to be downloaded

& used on Laptops/PCs

DE

SK

TO

P W

AL

LE

TSArmory, Multibit, Msigna

and Hive to mention a FEW

Easy to Access.

Available for Different OS

– Windows, Mac OS and Ubuntu.

MO

BIL

E W

AL

LE

TS

ON

LIN

E W

EB

W

AL

LE

TS

PH

YS

IC

AL

W

AL

LE

TS

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

BitcoinQt is the First ever built bitcoin CLIENT WALLET

BIT

CO

IN

C

LIE

NT

S

WA

LL

ET

S

Original bitcoinwallet 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

HA

RD

WA

RE

W

AL

LE

TS

BITCOIN ARTIFACTS

They DON’T EXIST

ANYWHERE, even

on a hard drive

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

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

Conduct a SEARCH based on BLOCK

NUMBER, ADDRESS,

BLOCK HASH,

TRANSACTION

HASH or PUBLIC KEY

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

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

BITCOIN-BLOCK FOLDER ANALYSIS


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

Chainstate subdirectory- it is a

database with a compact

representation of all currently unspent

transactions and some metadata about

where the transactions originated


Database subdirectory -

Contains database journaling

files


Number of

blocks preceding particular blockon a block chain.

Genesis block has a height of zero

because zero block preceded it.

20-byte hash formatted

using base58check to produce either a P2PKH or P2SH

Bitcoin address

00000000001F1tAaz5x1HUXrCNLbtM*****

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.

1.46 × 10^48 possible

Bitcoin Addresses

that gives every

person on Earth

2.05×10^38 Different

Addresses

Bitcoin Mixer is an Anonymous Service, that confuses the trails

of Bitcoin transactions.

PROJECT TITANIUM : Main thrust of the European

Union’s Titanium Project is to Monitor blockchains,deanonymize wallet addresses, surveil dark netmarkets, and block terrorists and money launderers.TITANIUM, which stands for Tools for the Investigation ofTransactions in Underground Markets

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

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

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

• 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

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

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”

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

Ulb

richt

Ross

[email protected]

https://about.me/anupam.tiwari

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