A large corporation has data centers geographically distributed across multiple continents. The
company needs to securely transfer large amounts of data between the data center. The data
transfer can be accomplished physically or electronically, but must prevent eavesdropping while
the data is on transit. Which of the following represents the BEST cryptographic solution?

A.
Driving a van full of Micro SD cards from data center to data center to transfer data

B.
Exchanging VPN keys between each data center via an SSL connection and transferring the
data in the VPN

C.
Using a courier to deliver symmetric VPN keys to each data center and transferring data in the
VPN

D.
Using PKI to encrypt each file and transferring them via an Internet based FTP or cloud server

Explanation:
A virtual private network (VPN) is an encrypted communication tunnel that connects two systems
over an untrusted network, such as the Internet. They provide security for both authentication and
data transmission through a process called encapsulation.
Secure Sockets Layer (SSL) can be used to exchange the VPN keys securely. SSL is used to

establish secure TCP communication between two machines by encrypting the communication.