Credit card numbers are protected during online and offline transactions using encryption and CVV numbers, as Investopedia claims. Online transactions require different security measures from offline transactions.
Credit card use is protected online by making credit card numbers more difficult to obtain and use by themselves, as reported by Investopedia. Encryption disguises credit card numbers as they are transmitted and only allows the recipient to decrypt numbers, as noted by Slate. Data encryption prevents outside parties from reading the transmission and obtaining identifiable personal information. A public key is used to encrypt the data, and a private key utilized by the merchant's payment processor is required to decrypt the information. Computer servers verify available account balances and ensure the customer is able to pay.
CVV numbers placed on the back of credit cards provide additional security, as stated by Investopedia. Online credit card transactions require the CVV number, which makes credit card numbers useless by themselves. When credit cards are used in-person, the magnetic strip on the card secures the personal account information so only the merchant terminal reader can retrieve and use it. Some credit cards have additional security measures, such as the use of chip and PIN technology.