Blockchain tutorial 27: Bitcoin raw transaction and transaction id Video Lecture | Blockchain Tutorial: A Fundamental Guide - Cryptocurrency

in this video I will show you what
action is and how the trends
elated
a road transaction is a way to construct
the transaction by specifying the
unspent transaction output which fit
going to spend and where to send them
this rotten
section can be signed with your private
key and the signed transaction can be
broadcasted to the Bitcoin network
it is intense
Felker's or very sophisticated end users
for low level access to transaction
creation and broadcast
in part 26 of this video series I've
already demonstrated how to create a raw
Bitcoin transaction
in part 26 I have created this
transaction output in this video I will
dive deeper in the creation of a
transaction this part in particular
but instead of using this transaction
I'm using the most simple transaction I
could find and that is the very first
transaction ever created on the Genesis
block
for the demo the following three links
are used
this link this link and this link all
three links can be found in the
description below
open the browser and go to blockchain
info
enter block number zero
this is block number
the Genesis block
as you can see that this is the coinbase
transaction it has no input it has only
an output this value is a transaction ID
or transaction hash I will show you how
this value is created click on this link
so this is a
section
the size is 204 bytes
and the minor in this case
knock model receive 50 bitcoins on this
address
before I can continue I first have to
explain what a big-endian
and a little endian is
big-endian means a machine stores the
most significant byte first
little-endian means the machine stores
the least significant byte first this is
a hexadecimal value in big-endian if you
want to consider this hexadecimal value
in the little endian way we take the
least significant byte and store it
first then you take the second this
significant byte a place it over here
then this value goes over here this
value goes over here this value goes
over here and this value goes over here
this hexadecimal value is now stored in
a little endian way usually values are
stored big-endian
Toshi is the smallest
of Bitcoin
100 cent one cent is the same as one
$100,000 one Bitcoin is the same as 100
million Satoshi's once the toshi the
same as one 100 million of a Bitcoin
download this file
this file
and go to this page
this is the Bitcoin protocol
station this part describes a Bitcoin
transaction this is our downloaded
bitcoin Genesis process action text file
right a transaction looks like this
so if you look at the protocol
datian the first four bytes contains the
first number
this is the first number and the test
for bytes and it's correct
by the number of transaction input we
have one transaction input and then we
have to specify the transaction inputs
here you see transaction in
and here is the disk
transaction in
it has previous outputs
here is a description of previous
outputs
scroll down previous output should have
a hash of the reference transaction and
the index of the specific output in the
transaction but you don't have an input
so we have to specify all zeros in here
in total 32 bytes
and because we don't have an index value
so we have to put in this hexadecimal
value in total 4 bytes
so this is transaction in followed by
the script length so 4d is the script
length the extra decimal value for D is
77 decimal this value is safety seven
bytes long followed by a sequence this
is sequence at this point it is not
important to know what this value is in
a later video
I will talk more about the script
signature and the script public key
they have looked at the transaction
input side now we have to look at the
output side here are the output so first
we have to specify the number of
transaction output that is 1 and then we
have to specify the transaction output
this is transaction in this a
transaction our structure we have to
specify the transaction value
transaction value we know that it is 50
bitcoins we have to convert it in
Satoshi's
and then consider two an hexadecimal
value which is this value
big endian we have to convert it into a
little endian
that is this notation
followed by the script length that is 43
a hexadecimal value it has the decimal
value 67 which means this value is 67
bytes long
already talked about the transaction
output then followed a long time and
this is the long time or zeros
so this is our
transection
the next step is to take all these
values this this this is this follow to
this without the colon
this
this-this-this without the Coulomb this
value and this value and append it to
each other you will get this long string
so this long string is the Royal
transaction in hexadecimal value the
next step is to confer this row
transaction value into a transaction
hash or transaction ID this stereo
the transaction ID or transaction has is
a long string of numbers for example
this long string the transitioned idea
can be used to look up a transaction on
the blockchain
transaction IDs are also used to create
a miracle tree more about this in a
later video
a Bitcoin transaction ID is always 32
bytes or 64 characters and contains
hexadecimal values
to calculate a transaction ID of a
transaction
the rotors action represented by this
variable we need to convert this road
transaction head string into the
corresponding Unicode and then assign it
to this data variable apply the sha-256
hash function twice on the data variable
and assign result to the hash variable
last step is to take a little endian
order of this hash and this is the final
result the hash little-endian is the
transaction ID
this is the calculate transaction ID
Python script which I have downloaded
this is our road transaction
coppy
we place this value with the copied
value watch out that you only replace
this value and don't change this part
I've already done it we conclude this
hexadecimal string into a Unicode cell
you then apply the sha-256 hash function
twice this line convert this value into
a big-endian order and this line
converted in the little endian order of
extra information and print out the
unicode information over here now let's
execute the script
you
if you look at this failure this is our
section hash if you copy
go to the blockchain info website and
paste the transaction hash in the text
box
search for the transection
as you can see that
has been found
if you look at this line this message
was put in by Satoshi Nakamoto
the message refers to this newspaper
article
the message was embedded in the script
signature in the latest video I will
talk more about script signature and
script public key
there are online tools available which
converts this road transaction into a
more readable text like this
copy the rotor section
go to www.hsn
let's cryptocurrencies less brainwallet
HTML this URL can be found in the
description below warning use this tool
only for educational purpose only click
on this transaction link and select raw
transaction in the row transaction field
paste your rotor session hexadecimal
value
as you can see over here it also
calculates a transaction - over here
thanks for watching I hope you enjoyed
the video please hit the like button and
don't forget to subscribe if you have
questions leave your comments below I'll
do my best to answer them