The system will also feature a “Cashier” function. Money must enter and exit the system. For example, someone may want to buy a digital certificate, or liquidate a digital certificate. The Cashier receives fiat and/or cryptocurrencies, and issues digital debt-letters by sending crypto-keys for the letters to the person depositing the money. Letters are issued in the smallest increments of the currency (i.e. fraction of cents, not dollars). In the case someone wants to liquidate his digital certificate holdings, they may trade them all against debt-letters. They would then trade those debt-letters with the Cashier for fiat or cryptocurrencies in the physical world. The BLX Cashier will only accept BLX-issued digital debt-letters. Therefore, if someone issues their own debt-letter, they must either provide their own cashier or gain permission from other entities’ cashiers.
To protect the Cashier functionality of the system from abuse and fraud, the company will employ the following security measures:
(a) Debt-letters will have a 48-hour waiting period before payment in any fiat or cryptocurrencies is executed, and
(b) Any party exchanging debt-letters has two private security keys. Both private security keys are owned by the participant sending the debt-letter to a third party. One key allows the participant to sign and send the debt-letter to the party’s public key (Cashier or any private person), and the other private key allows the participant to block the clearance of the debt-letter for five days (as well as removing the possibility of clearance to any digital currency). In the case that the second private key is executed, the Cashier can only clear the letter to a physical bank account once the bank account has been shown to the person entering the security key. Once the second private key is entered the debt- letter is flagged forever and anyone can see that this is a flagged debt-letter. Therefore, when a person would steal debt-letters (or the private keys from someone), and would hold them, he would be forced to eventually clear it via a physical bank account, resulting in the account being disclosed to the original holder five days prior to clearance. This security measure is to overcome negligence of participants who fail to keep their keys secure as well as weaknesses of digital wallets.