Imagine if all your business contracts were sent to customers written on postcards. Everyone who happened to see the postcard could see exactly what you were going to charge the customer, how many of your product the customer is going to order - and all of the information about the customer.
Your competition, naturally, could take that information and send a contract to that customer of yours that undercuts your proposal and offers better terms. They could also share that information with others to let them know that this customer buys from you. (Or, at least, they used to!) Your customer, too, could potentially see what you are charging other customers.
Now... STOP imagining - THIS IS HOW THE INTERNET WORKS TODAY!
In the physical world, of course, we don't do this. We fold up contracts and we put them in envelopes. We might then put the sealed envelope inside a larger courier envelope. If we are really paranoid we might put them inside "tamper-proof" envelopes - or envelopes that can only be opened with a specific key.
But in the online world we don't have these same protections by default. Every message you send has historically been broken down into many small packets and sent - unprotected - across the Internet. This is the digital equivalent of sending everything on postcards.
We need to protect our online business communication.
We need digital envelopes
The solution we have is to use encryption to protect our online information. We need to stop sending postcards - and put digital envelopes around all of our data.
We need to encrypt the information when we are sending it between people. We do this today online with technologies such as the HTTPS "lock" we see in our browsers (which is actually Transport Layer Security or "TLS", formerly called "SSL").
If we are to have safe, secure, and trusted economic transactions over the Internet we must know that only the people involved with the transaction can see the information.
We need digital envelopes - THAT is why we need encryption.
P.S. Some readers might notice that regular physical envelopes can be opened at the post office, in the company mail room, by customs officials at a border, or by other people who intercept the envelopes. That is true in the online world, too. There are different types of encryption. Some can be intercepted by people in the middle (what we call "hop-by-hop" encryption) and some types of encryption are secure between the sender and receiver (what we call "end-to-end" encryption). But that's the topic for another blog post...