In order to register a vehicle, its authentic title must be submitted to the Department of Motor Vehicles. Scans, copies, and images are not accepted for registration.
So your vehicle's authentic title is an important document - this article describes how to secure it against theft.
The security feature built into every US vehicle title
Every vehicle title has text like this: Any alteration, use of correction fluid, or erasure voids this certificate.
Here's that text from a Montana title:
As soon as you buy a vehicle, write your name - or ask the seller to write your name - in the buyer's section of the vehicle's title.
If someone intercepts your title and crosses out, whites out, or erases your name, the title will become void.
Security on an example title
Let's look at an example.
Below is a California title, with the seller's section marked in red, and the buyer's section marked in blue.
This title is SAFE: the seller has not signed the seller's section of the title.
DANGER: seller has signed, and buyer's section is blank
Below, we see that the seller has signed the seller's section, and the buyer's section is blank:
A vehicle title with a complete seller's section and a blank buyer's section is a bearer instrument - it belongs to whoever physically holds the title.
SAFE: seller has signed, and a name is written in buyer's section
Below, we see that the seller has signed the seller's section, and a name is written in the buyer's section.
Now that John Smith's name has been written in the buyer's section, the vehicle can only be registered to John Smith.
SAFE AND COMPLETE: seller has signed, a name is written in buyer's section, and the buyer's section is signed
Below, we see that the seller has signed the seller's section, a name is written in the buyer's section, and the buyer has signed.
This title is safe and complete - ready for registration.
Conclusion
So, to keep your vehicle's prior title safe after purchase, remember to write - or have the seller write - your name in the buyer's section of the title.