using data encryption techniques to code data so that it makes no apparent sense
When you bank online, after you’ve logged in, you will notice that the http in the address bar has changed to https. This indicates that a secure connection between your computer and the bank's computer has been established. Data sent between the two computers is encrypted so that anyone trying to intercept your data will receive meaningless data. The data can only be decrypted into readable data by using a key that is known only to the two computers - yours and the bank's.