Sentry 2020 provides encrypted virtual volumes. All information (files, folders, file system structures) stored on a Sentry volume is transparently encrypted/decrypted every time an application performs a read/write operation on the volume. Without a correct password, Sentry volume is just a file with encrypted contents. When the correct password is provided, the volume is mounted, and appears as a drive letter (Win 95/98, Win NT) or as a folder in the root directory (Win CE). Any application can then work with the contents of the mounted Sentry volume without noticing the encryption being performed on the fly.

When mounted, a virtual volume looks like an ordinary disk and you can store your files on it. Every read operation on the volume causes decryption of the data and every write operation causes encryption. This approach is called "transparent encryption" and insures that your data is always stored in a safe, encrypted form, and yet appears in its natural form when you wish to use it.