SJ

SJ is a jabber-client communication software that offers integrated encryption in automatic mode. This client employs the latest advancements in cryptography, data transmission and reception methods, and user interface creation. It's built on WPF, a .NET framework extension, and the language of XAML, enabling the creation of interfaces for current and upcoming Windows versions.

Encryption on SJ relies on OpenPGP, an asymmetric encryption system that uses two keys: public and private encryption for decrypting data. Members share their public keys, encrypt messages with them, and private keys are used to decrypt received messages. Users can also set and control their keys entirely. This encryption history feature is vital for safeguarding personal data from unauthorized computer access or third-party encryption programs. SJ's XMPP protocol uses open library agxXMPP and implements XEP-0027 extensions with added proprietary protocol extensions, resulting in full compatibility with other popular jabber-clients. It also features a fully automatic exchange of organized public PGP-key, saving users from installing additional software to support OpenPGP encryption.

Paid version features include user commentaries on contacts, message history encryption, anti-capture mode, automatic file transfer via SendSpace archive, and OpenPGP key length increased to 4096 bytes. SJ is an excellent software for securing personal correspondence.