The internet has transformed the way we communicate, bringing convenience and connection. However, digital communication entails privacy risks. The information we send online can end up anywhere and anyone can access it. Users can now use encrypted and ephemeral messaging platforms to address these concerns. PrivNote is an online private message box that lets users exchange self-destructing text messages.
what is private message? PrivNote bills itself as “the most secure” way to send private messages online. It allows users to type or paste text into a box on its website and send it to a recipient via a generated link. No forwarding is possible and disappears from PrivNote’s server after being read once. The service offers a browser-based interface requiring no logins or software downloads. This ease of use has contributed to PrivNote’s popularity for one-off private communications. PrivNote asserts that its security features make it suitable for transmitting confidential information from sources to journalists and for other sensitive communications. However, how valid are these claims? Let’s take a technical look under the hood.
Encryption protocol
The key security component of any private messaging application is its encryption protocol. Encryption scrambles data using algorithms and keys so that only authorized parties decipher it. PrivNote uses client-side JavaScript encryption. This means message encryption happens entirely within the sender’s browser before the data gets sent to PrivNote’s server. The server never receives the unencrypted message text. PrivNote uses 256-bit AES encryption in Galois Counter Mode. It is considered very secure and resistant to brute-force attacks. Algorithms have no known weaknesses. The keys are generated on the fly by the sender’s browser.
Metadata protection
In addition to message text, communications metadata reveal sensitive information. This includes data like who contacted whom, when, and from which IP addresses. PrivNote provides metadata protection by not logging IP addresses or retaining message data. Messages are encrypted client-side and then deleted from PrivNote’s server immediately after the first viewing. No metadata gets retained about senders or recipients. The service is accessed entirely through the web interface. There are no associated mobile or desktop apps that could betray additional metadata. The transient nature of PrivNote messages limits the exposure of metadata like message timestamps. Though the service itself doesn’t log metadata, users’ browsers will retain some metadata locally such as access times and sites visited. But PrivNote itself retains no long-term metadata on communications.
Message lifetime
PrivNote messages have a maximum lifetime of 7 days but self-destruct after being opened once. Links always lead directly to the unencrypted message text. There is no expiration notice or additional confirmation step. The transient, one-view nature of PrivNote messages provides security against retroactive breaches. Even a total system compromise after the fact couldn’t unveil messages already destroyed after reading.
- Recipient logs/prints messages before the self-destruct.
- Network attackers intercept the message in transit.
- Browser caches store artifacts of visited PrivNote links.
- Sender is coerced to resend or disclose the message.
So while PrivNote deletes messages quickly, proper operational security is still required around handling of the links before they vanish.