Double Spending "it is nothing but the one type of problem when using the Digital Currency"

1. Bhavadip GothadiyaBhavadip Gothadiya
DIV-1DIV-1stst
Roll no-58Roll no-58
Created By BG02/05/16

2. Topic:
Double Spending
Created By BG02/05/16

3.  The user can spend digital money at any shop accepting e-cash,
without having to open an account these or having to transmit
credit card number
 As soon as,
customer want to make a payment,
software collects the necessary amount from the stored tokens.
Created By BG02/05/16
Using the digital currency

4.  Problem in bilateral transaction
 Equivalent to bouncing a check
 Possible as it is very easy to make copies of the e-cash
 If anonymity (for freedom of usage is relaxed, double spending
problem can be avoided
 Here, a consumer is issued a bank note on his/her unique license.
Created By BG02/05/16
Double spending::-

5.  When money is transferred it is transferred to that other
person’s license
 Bit of information added to the note based on bank’s
serial number and old owner’s license
 If double spending is now tried, cheater can be
immediately caught
 But, bank can tell precisely the buying habits
Created By BG02/05/16

6. Detection of double spending
02/05/16 Created By BG

7. 02/05/16 Created By BG
Payer Payee
Bank
Digital
Currency
Server
Database of spent “notes”
Issue cash
Check for double
spending
Transfer digital cash

8. To uncover double spending
 Bank must check notes with database of spent notes.
 Like unique serial numbers is paper notes, some form of
registration should be there to uniquely identify all notes
issued globally.
 But for most systems, which handle high volumes of micro
payments, this method will be too expensive.
 Also, banks have to carry added overhead because of
the content checking and auditing logs.
02/05/16 Created By BG

9. Change problem
 E-cash has its to carry to be easily divided into smaller
amount
Created By BG02/05/16

10.  To deal with:
 Bank can issue users with enough separate electronic coins
of various denominations
 Payees returns extra change
 It would be cumbersome in communication and storage
02/05/16 Created By BG

11. Thank u
Created By BG02/05/16