Coding Challenge #48 - Data Privacy Vault

This challenge is to build your own Data Privacy Vault. A Data Privacy Vault is a way to keep sensitive information safe. The vault stores the data and controls who can get to it, making sure it's managed, watched over, and used carefully.

Every business has sensitive data, whether it's about people's health (medical records), their payment details (credit card numbers), or other personal information (names and addresses).

At the same time every business wants and needs to leverage that data: analysing trends, processing payments, confirming someone's identity or simply delivering the product to the customer. The data is incredibly valuable so keeping it safe and secure is essential to the ongoing operation of a business as well as compliance with industry and legally required standards.

A data vault helps businesses achieve this by separating sensitive data and storing it in a secure service or ‘vault’. This vault then controls access to the data only when absolutely needed.

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The Challenge - Building Your Own Data Privacy Vault

For this challenge we’re going to build a service that can function as a Data Privacy Vault, that’s the green bit in the high-level diagram below that conceptually shows where it would fit in some sort of production system.

Our service will provide a HTTP based API that can be used to send sensitive data to be stored in the vault, receiving back a token that can later be used to retrieve the sensitive data by an authorised user/service.

To understand why the Data Privacy Vault is preferable to just encrypting the data check out Wikipedia’s article on Tokenization.

Step Zero

In all the best programming languages we index arrays from zero. Coding Challenges continues that trend starting every challenge from step zero.

As usual, step zero is to set up your IDE / editor of choice and programming language of choice. We’re going to build a service with HTTP based API so pick your favourite language to do that with or the one you most fancy learning.

Aside: Some programming language index arrays from zero because arrays are essentially a pointer to the beginning of a contiguous block of memory and an offset from that point. In other words, if you’re familiar with C then array[index] is equivalent to *(array + index).

Step 1

In this step your goal is to create a simple tokenisation service that can create tokens and return their value, for the moment storing the data in memory is fine.

Once this is done you should have two endpoints:

Endpoint: /tokenize

Method: POST

Request payload:

{
	"id": req-12345”,
	"data": {
		"field1": "value1",
		"field2": "value2",
		"fieldn": "valuen"
	}
}
        

Success response: HTTP Code 201

Payload:

{
	"id": req-12345”,
	"data": {
		"field1": "t6yh4f6",
		"field2": "gh67ned",
		"fieldn": "bnj7ytb"
	}
}
        

Don’t forget to create the appropriate error response codes.

Endpoint: /detokenize

Method: POST

Request payload:

{
	"id": req-33445”,
	"data": {
		"field1": "t6yh4f6",
		"field2": "gh67ned",
		"field3": "invalid token"
	}
}
        

Response:

	"id": req-33445”,
	"data": {
		"field1": {
			"found": true,
			"value": "value1"
		},
		"field2": {
			"found": true,
			"value": "value2"
		},
		"fieldn": {
			"found": false,
			"value": ""
		}
	}
        

Don’t forget to create the appropriate error response codes and to handle a token not being found.

Continued...

You can find Step 2 and beyond on the Coding Challenges website as build your own Data Privacy Vault.

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