Without encryption, the data you send or store can be read by anyone who gains access to it. One option is to use a virtual private network (VPN), which is vital if you’re using a public network. But you can also often encrypt files in cloud or external storage. Some cloud hosts will do this automatically, but you’ll have to encrypt any external data yourself. To protect your data from intruders, consider encryption software, such as TrueCrypt, if you store sensitive data on your portable drives.