What is an Internet-pager?

Instant messaging, or IM, is a form of real-time communication between two or more users. IM users communicate by transmitting text. The text is conveyed via computers connected to the Internet.

When choosing a communication network, most people are guided by their friends’ or colleagues’ preferences. But if some of them use, for example, ICQ or MSN, then they have to install both of these applications. Abroad, the networks like AIM and Yahoo! are also very popular! And even in Russia Skype and Googe Talk are often used.

Besides, we should mention a very popular form of XMPP technology, which is in contrast to some other internet-paging systems (IM - instant messaging systems) are completely open and free (networks like AIM, ICQ, MSN and Yahoo! are paid through advertising from the banners embedded within the software). The main advantage of XMPP is that every person has the right to open its own XMPP server; the latter can even be set apart from the global network.

What are the particulars of SJ IM?

PGP Logo

SJ IM software is a XMPP client with built-in encryption. You can download it from our website to install onto your computer. This application helps you securely protect personal correspondence, regardless of whether you're using XMPP protocol or ICQ.

The latest achievements in the field of cryptography, data transmission/reception methods and the user interface creation were used in the development of the current XMPP / ICQ client. The software is built on WPF (Windows Presentation Foundation) and XAML language, allowing the creating of a new generation of interfaces compatible with current and future versions of Windows. Moreover, WPF is .NET framework’s ideological continuation.

SJ supports many Internet messengers:

Instant Messengers

How does encryption work?

Encryption works on OpenPGP systems based on PGP (Pretty Good Privacy) – a library of features allows message encoding. This cryptosystem of asymmetric encryption uses two keys: open (to encrypt) and closed (to decode). Thus, users who wish to keep their correspondence a secret, simply exchange open (public) keys, and send each other messages encrypted by these keys. When the user receives the message, they enact their own private (private) key to decrypt the data. The system guarantees privacy while keeping the key a secret. You must understand that you can set the length of the key and control it. The program has a built-in feature allowing the monitoring of the actions it performs. Therefore, you can clearly follow on your monitor the message encryption process.

PGP Schema

Off-the-Record Messaging

Off-the-Record Messaging (OTR) — is a cryptographic protocol that provides strong encryption for instant messaging conversations. OTR uses a combination of the AES symmetric-key algorithm, the Diffie–Hellman key exchange, and the SHA-1 hash function. In addition to authentication and encryption, OTR provides perfect forward secrecy and malleable encryption.

The primary motivation behind the protocol was providing deniability for the conversation participants while keeping conversations confidential, like a private conversation in real life, or off the record in journalism sourcing. This is in contrast with other cryptography tools that produce output which can be later used as a verifiable record of the communication event and the identities of the participants. In most cases, people using such cryptography software are not aware of this and might be better served by OTR tools instead. The initial introductory paper was named "Off-the-Record Communication, or, Why Not To Use PGP"

The OTR protocol was designed by cryptographers Ian Goldberg and Nikita Borisov. They provide a client library to facilitate support for instant messaging client developers who want to implement the protocol.

In addition to providing encryption and authentication — features also provided by typical public-key cryptography suites, such as PGP, GnuPG, and X.509 (S/MIME) — OTR also offers some less common features:

Why do we need encrypted correspondence history?

This question is rather rhetorical, because there are many people who do not understand the reason for using correspondence history if it’s not encrypted. They have to invent different ways of protecting personal information. As an example of the necessity of encrypting the correspondence history, we can cite the use of the correspondence by third parties for illegal purposes.

You leave your job for thirty minutes to perform an urgent mission; the congestion and distraction makes you forget to turn your computer off which happens to contain a hard drive holding correspondence with friends and colleagues or information that might incriminate you. During this time, someone else has access to the correspondence, which is not encrypted and kept unprotected.

History encryption feature is available in the paid version of SJ IM Premium.

How does the data transfer work?

Message delivering in SJ IM is performed through XMPP or OSCAR (for ICQ clients) protocols. After developing the XEP-0027 expansion and adding its own extension to the protocol, our team not only achieved full compatibility with all popular XMPP clients and standard encryption system support working on the popular PSI client, but was also able to successfully organize a fully automatic exchange of PGP public keys. This brings SJ IM client to a new level where there is no necessity to install any additional applications (e.g. GNUPG under PSI) in order to support OpenPGP encryption. Unfortunately, for now this extension is only supported by SJ IM.

The full support of XMPP protocol is realized using agsXMPP open source library, which is by far the most complete and stable one.

Why do we need to transfer files via Sendspace?

It should be noted that transferring files through an independent source, in automatic mode, in the archive protected by a 32 character password, is much safer. To do this, you only have to press a single button. www.sendspace.com allows you to download and upload files, providing the highest safety for transmitted information.

Why should I lock the computer when I'm not around?

The paid version of the program has a feature called "anti-capture". The goal of the feature is very simple and consists of the following:

  1. We set the hotkey for the application of the feature.
  2. Press it and see the Lock screen.
  3. We leave on business, or for a coffee.

Do not forget that there are different ways to access your data. Be vigilant!

You can download the app and use it for fun.

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