Cryptogram.

Cryptogram is:
1. The only anonymous messenger without registration and login.
2. The only messenger that doesn’t use public keys.
3. The only post quantum encrypted messenger persistent to quantum computing.
4. Perfect secrecy with one-time pad encryption that proved by Claude Shannon in 1949.
5. Perfect random generator with physical process in core: magnetic field ripples.
6. The only messenger with secure key exchange between to closely spaced devices

How to use it:
1. Meet your partner off-line
2. Purchase one Key pack for the price of a cup of coffee.
3. Share the keys, let your partner scan QR-code to accept the keys
4. Send encrypted messages at a distance via the internet without risk.

Cryptogram is a encrypted messaging app for private texting. Use the strongest cryptographic technology for encrypting messages with one-time pad key. Pass the secret keys from one device directly to another without internet.
The real privacy messenger does not rely on the Public keys like all the other messengers. According to numerous reports on post quantum cryptography, one day all public keys will be compromised with quantum computers and all encrypted messages will be read. Today only cryptogram with its one-time pad provides the complete and theoretically proved secrecy.
cryptogram is a paid private messenger because we make money by selling software products, not by trading upon your secrets.
Our private texting app uses one-time pad key and XOR operation for encrypting private text messages. Every text message encrypted with a pre-shared unique random key that is bigger than the message. The keys are generated and shared during the meeting between the two users over local peer-to-peer secure TLS connection. The Key pack contains 2000 keys. During the meeting two users can repeat the key sharing procedure many times, generating 2000 keys every time, each user gains 1000 keys for outgoing and 1000 keys for incoming messages.
With the very long one-time keys the users can send messages remotely over internet. After the message have been sent, the OTP key is deleted from the sender's key set, and in the same way, after receiving and decrypting the private text message, the key is deleted from the receiver's key set.
The application doesn't require registration and login, it doesn't process or keep any user identification data, and so notification can not be sent to a user. Thus it is a user's will to launch application, check and download incoming secret messages.
The maximum private text message size is 200 characters. A recipient has 5 days to download a message after that period the message will be deleted for security reasons.