Final answer:
The encryption or safeguard on an e-card is often provided by a three-digit code known as the CVV, which is essential for card-not-present transactions.
Step-by-step explanation:
In many cases, the encryption or safeguard on an e-card comes in the form of a three-digit code on the back. This code is commonly referred to as the Card Verification Value (CVV) and is an important security feature in card-not-present transactions, such as online purchases, where the merchant cannot physically inspect the card. The CVV is separate from the magnetic strip, microchip, or any pictures on the card, and it helps to verify that the physical card is in the possession of the cardholder.