A secure end-to-end messaging
system utilizes location-based computer readable media encoding cryptographic codes to facilitate
encryption and decryption of messages between electronic devices. A first device reads a cryptographic code from a first media, encrypts a message, and transmits it to a
server where only the
ciphertext is stored. A second device, at a different location, reads a second cryptographic code from a paired media to decrypt the message locally. The codes represent symmetric keys or asymmetric key pairs, enabling message authenticity
verification through digital signatures. Cryptographic data embedded in URL fragments to avoid transmission to the
server, enhancing security against interception. The media also encodes permissions, expiration dates, and
device identifiers for granular control and notification capabilities. The
system supports hierarchical access, group messaging, and various formats including audio / video, ensuring scalable, secure, and verifiable communication across distributed users without exposing
plain text or private keys to the
server.