Transferable Digital Notes Project

Validate TDN

A TDN is valid and can be used for a payment or transfer if its status is Active. If the status is Canceled the TDN has been used in a Split or Consolidate or Redeem transaction. If the status is Blocked the TDN is part of an investigation by an authorized authority. When the status is Canceled or Blocked the TDN cannot be used for a payment or transfer.

The easiest way to check the status of a TDN by is using the Central Bank website. Anybody in the possession of a TDN can check if it is valid on this website. The user will cut and paste the TDN Signature in the appropriate field of the 'Validate' webpage or scan the TDN barcode id the device accessing the site has a webcam. The return consists of the TDN status, its value and if status is Blocked a message with the contact information of the investigative authority that blocked the TDN.

TDN Applications or eCommerce website use the Validate TDN API call to implement validation. The return value of the call is used in the application as appropriate. When initiating a TDN transaction with an invalid TDN the API call will return the same value as the Validate TDN API call and the transaction will not be performed.

TDN validation is just a simple search of the TDN Signature in the repository. The execution is very fast.

A valid TDN does not guaranty that the TDN is not compromised. A TDN is considered compromised if the TDN Signature is in the possession of more than one entity. It is impossible know if a TDN is compromised until a transaction is perform on that TDN. If the legal holder of the TDN performs the transaction (except validation) the compromised TDN is canceled and the fact that was compromised is obviously irrelevant. If however a fraudulent holder of the TDN uses it then the legal holder is in the possession of a canceled TDN. He/she may request an investigation to identify the fraudulent use of the TDN.

There may be more than one owner of a TDN when the parties involved in a transaction trust each other and the new TDN holder does not request ownership of the TDN. Theoretically the TDN is considered compromised but in this situation it is less likely a fraudulent transaction will be performed on that TDN. The new owner of the TDN assumes that the previous owner was not unknowingly in the possession of an already compromised TDN.

Here is how the status of TDNs looks in the repository:

Status : 0 = canceled, 1 = active, 2 = blocked

tdn_id       tdn_issue_date      tdn_token        status value    Status_chg_date  Transct_ID
------------ ------------------- --------------------- - -------- ------------------- ------
4A464C593... 2020-06-11 19:07:07 4A464C59344D4E5668... 0 00010000 2020-06-11 07:07:20 100000 Get TDN
624352323... 2020-07-20 11:06:10 64E5668414D0A24352... 1 00010000 2020-07-20 06:06:10 100000 Ownership

6A2B7A337... 2020-06-10 20:07:06 6A2B7A33744A657468... 0 00009000 2020-06-10 07:07:19 100001 Consolidate
6F316B657... 2020-07-19 10:06:19 6F316B657077735834... 1 00010000 2020-07-19 06:06:06 100001 two TDNs
232307591... 2020-06-11 19:07:07 848360A664A464C593... 0 00001000 2020-06-11 07:07:07 100001
A33744A65... 2020-07-20 11:06:11 6848360A6641654262... 1 00001000 2020-07-20 06:06:17 100002 Split TDN
B65707773... 2020-06-10 20:07:06 6A2B7A33744A657468... 1 00009000 2020-06-10 07:07:06 100002
C59344D4E... 2020-07-19 10:20:20 6F316B657077735834... 0 00010000 2020-07-19 06:06:07 100002

4A464C593... 2020-06-11 19:10:07 14D0A5A4462674974A... 0 00030000 2020-06-11 07:07:96 100003 Get TDN
344D4E6F3... 2020-07-20 06:19:10 5A4462674970546243... 1 00000340 2020-07-20 06:11:17 100003 Ownership
64C59344D... 2020-06-10 07:06:06 6A2B7A33744A657468... 0 00053476 2020-06-10 07:20:06 100004
352323075... 2020-07-19 06:07:07 6F316B657077735834... 2 00050000 2020-07-19 06:10:07 100005 Blocked TDN