Privnote is a secure online service that allows users to send encrypted notes that can only be read by the intended recipient. Notes are encrypted using AES-256 encryption and a unique key is generated for each note. The key is sent to the recipient via a secure link and can only be accessed by the intended recipient. Once the note is read, it is automatically deleted and cannot be accessed again. This online service is useful for sending sensitive information such as passwords, personal information, and confidential documents.