-The Secure Internet Live Conferencing (SILC) protocol provides secure
-conferencing services over insecure network channel. The SILC is IRC
-like protocol, however it does not support IRC. Strong cryptographic
-methods are used to protect SILC packets inside the SILC network. SILC
-provides all the common conferencing services like channels, channel
-messages, private messages, nicknames and various commands. Difference
-to other chat protocol is in the design of the protocol. The SILC
-protocol has been designed from the day one security in mind and it
-shows in the protocol design.
-<p>
-
-Generally it is assumed that the SILC Network is trusted. This means
-that clients can fully trust the servers and routers in the SILC Network.
-In real life this is not always possible. In the Internet it is possible
-that some server or router would get compromised by a malicious
-cracker. However, if the SILC Network is closed network, for example
-inside a orgranization the assumption generally is true. The SILC
-protocol is secure even if the end users consider the network
-untrusted, and provides several ways to still have secure conversation
-on the SILC Network.
-<p>
-
-The packets in the SILC network are always encrypted. It is not possible
-to send unencrypted messages in SILC. This assures that end user cannot
-even accidently send unencrypted messages while thinking that it is
-encrypted. This is the problem of most other chat protocols that provide
-so called plugin encryption. They are not secure by default but try
-to provide security by applying external security protocol such as PGP
-or SSL. In these cases the security is achieved usually by encrypting the
-data while key management and other security issues may be left out, leaving
-the implementation vulnerable to various security problems. The other
-problem is also that the external protocols tend to leave the network
-only partly secured; usually only two points in the network are secured
-with for example SSL. While SSL does provide provable security it is not
-enough to provide security for a chat network as a whole.
-<p>
-
-The network topology is also different to various other chat protocol,
-like for example IRC. IRC has tree style network where SILC has so
-called cellular network. A cell consists of a router, servers and clients.
-The cell can also have backup routers in case the private router becomes
-unresponsive.
+Secure Internet Live Conferencing, or SILC in short, is a modern
+conferencing protocol which provides rich conferencing features with
+high security. One of the main design principles of the protocol was
+security. Many of the SILC features are found in traditional chat
+protocols such as IRC but many of the SILC features can also be found
+in Instant Message (IM) style protocols.
+<p>
+
+SILC combines features from both of these chat protocol styles, and
+can be implemented as either IRC-like system or IM-like system. In
+fact, SILC removes the need to make such distinction between these
+two protocol styles. Some of the more advanced and security features
+of the protocol are new to all conferencing protocols. SILC also
+supports multimedia messages and can also be implemented as a
+video and audio conferencing system. The protocol is also compact
+and robust and suites well for mobile environments where the low
+bandwidth sets special requirements for protocols. All packet sizes
+in SILC can be even further reduced by utlizing compression.
+<p>
+
+The packets and messages in the SILC network are always encrypted and
+authenticated. It is not possible to send unencrypted messages in SILC
+at all. This assures that end user cannot even accidently send unencrypted
+messages while thinking that it is encrypted. This is one of the problems
+of most of the other chat protocols that provide so called plugin encryption.
+They are not secure by default but try to provide security by applying
+external security protocol such as PGP or SSL over the insecure
+protocol. In these cases the security is achieved usually by encrypting the
+data while key management, message authentication and other security issues
+may be left out, leaving the implementation vulnerable to various security
+problems. The other problem is also that the external protocols tend to
+leave the network only partly secured; usually only two points in the
+network are secured with for example SSL. While SSL does provide provable
+security it is not enough to provide security for a chat network as a whole.
+<p>
+
+SILC is secure in environment of mutual distrust between entities
+in the network. It is possible to encrypt messages end to end, so that only
+the sender and the receiver is able to encrypt and decrypt messages. It
+is also possible to send messages to group of users, so that only the
+specified group of users is able to encrypt and decrypt messages. Many
+times the protocol use keys that are generated by the servers, so that
+if other external key exchange methods fail the network still remains
+encrypted. However, it is always possible to negotiate and use locally
+generated keys to secure messages, so that the servers do not know the
+key.
+<p>
+
+Like so many other contemporary chat protocols, SILC too provides
+file transfer. It is possible to transfer files securely between users
+in the SILC Network. The actual file transfer stream is always sent
+outside the network peer to peer. Before the file transfer is started
+a key exchange protocol is executed to negotiate file transfer session
+key.
+<p>
+
+The SILC protocol also supports so called detaching, a novel idea where
+it is possible to detach from the server without actually quitting the
+network. It is then later possible to resume the connection back to some
+server in the network, and be like you were never gone.
+<p>
+
+The SILC protocol also allows distribution and exchange of public keys
+and certificates through the SILC network. It is also possible to fetch
+detailed user information from other users through the SILC network. It
+is possible to fetch for example users's business card, pictures,
+certificates, etc.
+<p>
+
+SILC protocol also supports services, which are extensions to the core
+protocol. They can be used to augment the features of the protocol or
+to add entirely new features without breaking backwards compatibility.
+Services can be negotiated online and authenticated with passphrases or
+with digital signatures.
+<p>
+
+The network topology is also different from traditional conferencing and
+chat protocols. The SILC network forms so called hybrid ring-mesh network
+at the router level, and star network at the server level. This sort of
+network topology allows better scalability and faster delivery of packets
+than traditional spanning tree style network. The router servers and normal
+servers also has the distinction that only router's know global information
+and keep the global network state up to date, and normal servers keep only
+local information up to date. This significantly increases the scalability
+of the network. The network also supports backup routers which can be
+used to protect the network against netsplits.