As cloud storage becomes more widely used around the globe, the recurring question of security remains a constant. Understanding how cloud storage security works helps to alleviate some of the worry.
First, data that is stored in the cloud is stored in an encrypted format. That means before a hacker can access the information they need to first crack the encryption. Reliable commercial cloud storage systems encode each user’s data with a specific encryption key. Without it, files look like nonsense and are unreadable.
Who has access to the encryption key? Most services keep the key, but it can be stored by the service provider or by individual users. Services access the key when a user logs in with a password, unlocking the data so the person can use it. This method is more suitable than users keeping the encryption key themselves.
The important thing is that the services have impregnable security practices that protect users’ data vulnerability. Otherwise, there is the danger of misuse or theft without the owner knowing about it.
If you are managing your cloud data security on your own, it’s best to first encrypt it using your own encryption software before uploading it to the cloud. Then upload the encoded file to the cloud. Then to get access to the file again, log in to the service, download it and decrypt it yourself.
You will not have the advantages of cloud services, like live editing of shared documents and searching cloud-stored files; and the company providing the cloud services could still modify the data by altering the encrypted file before you download it.
To best protect against that, use authenticated encryption, which stores the encrypted file as well as the metadata that indicates whether the file has been changed since it was created.
If you don’t want to learn how to program your own tools you can find a cloud storage service with trustworthy upload and download software that has been validated by independent security researchers. Or use trusted open-source encryption software to encrypt your data before uploading it to the cloud.