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12 <h1>Frequently Asked Questions</h1>
14 <i>Q: What is SILC?</i><br>
15 A: SILC (Secure Internet Live Conferencing) is a protocol which provides
16 secure conferencing services in the Internet over insecure channel.
17 SILC is IRC like although internally they are very different. Biggest
18 similiarity between SILC and IRC is that they both provide conferencing
19 services and that SILC has almost same commands as IRC. Other than
20 that they are nothing alike.
22 Biggest differences are that SILC is secure what IRC is not in any
23 way. The network model is also entirely different compared to IRC.
26 <i>Q: Why SILC in the first place?</i></br>
27 A: Simply for fun, nothing more. An actually for need back then when
28 it was started. SILC has been very interesting and educational
32 <i>Q: When will SILC be completed?</i><br>
33 A: SILC still has a lot things to do. The time of completion is much
34 related to how many interested people is willing to join the effort.
35 It will be ready when it is ready. The reason for release of the
36 current development version is just to get it out and people aware
37 that something like this exist. SILC is not ready for production
38 use so it is not expected that there is that much of a hype around
39 SILC. I don't have to hurry... :)
42 <i>Q: Why use SILC? Why not IRC with SSL?</i><br>
43 A: Sure, that is possible, although, does that secure the entire IRC
44 network? And does that increase or decrease the lags and splits in
45 the IRC network? Does that provide user based security where some
46 specific private message are secured? Does that provide security
47 where some specific channel messages are secured? Security is not
48 just about applying encryption to traffic and SILC is not just about
49 `encrypting the traffic`. You cannot make insecure protocol suddenly
50 secure just by encrypting the traffic. SILC is not meant to be IRC
51 replacement. IRC is good for some things, SILC is good for same and
55 <i>Q: Can I use SILC with IRC client? What about can I use IRC with SILC
57 A: Answer for both question is no. IRC client is in no way compatible
58 with SILC server. SILC client cannot currently use IRC but this may
59 change in the future if IRC support is added to the SILC client.
60 After that one could use both SILC and IRC with the same client.
61 Although, even then one cannot talk from SILC network to IRC network.
62 That just is not possible.
65 <i>Q: Why client/server protocol is based on IRC? Would it be more
66 interesting to implement something extensible and more powerful?</i><br>
67 A: They are not, non the least. Have you read the protocol specification?
68 The client superficially resembles IRC client but everything that
69 happens under the hood is nothing alike IRC. SILC could *never*
70 support IRC because the entire network toppology is different
71 (hopefully more scalable and powerful). So no, SILC protocol (client
72 or server) is not based on IRC. Instead, I've taken good things from
73 IRC and leaved all the bad things behind and not even tried to burden
74 myself with the IRC caveats that will burden IRC and future IRC
75 projects til the end. SILC client resembles IRC client because it is
76 easier for new users to start using SILC when they already know all the
81 <i>Q: Why SILC? Why not IRC3?</i><br>
82 A: Question that is justified no doubt of that. I didn't start doing SILC
83 to be replacement for IRC. SILC was something that didn't exist in
84 1996 or even today except that SILC is now released. However, I did
85 check out the IRC3 project in 1997 when I started coding and planning
88 But, IRC3 is problematic. Why? Because it still doesn't exist. The
89 project is at the same spot where it was in 1997 when I checked it out.
90 And it was old project back then as well. Couple of months ago I
91 checked it again and nothing were happening. That's the problem of IRC3
92 project. The same almost happened to SILC as well as I wasn't making
93 real progress over the years. I talked to the original author of IRC,
94 Jarkko Oikarinen, in 1997 and he directed me to the IRC3 project,
95 although he said that IRC3 is a lot of talking and not that much of
96 anything else. I am not trying to put down the IRC3 project but its
97 problem is that no one in the project is able to make a decision what
98 is the best way to go about making the IRC3 and I wasn't going to be
99 part of that. The fact is that if I would've gone to IRC3 project,
100 nor IRC3 or SILC would exist today. I think IRC3 could be something
101 really great if they just would get their act together and start
105 <i>Q: How secure SILC really is?</i><br>
106 A: A good question which I don't have a answer. SILC has been tried to
107 make as secure as possible. However, there is no security protocol
108 or security software that has not been vulnerable to some sort of
109 attacks. SILC is in no means different from this. So, it is suspected
110 that there are security holes in the SILC. These holes just needs to
111 be found so that they can be fixed.
113 But to give you some parameters of security SILC uses the most secure
114 crytographic algorithms such as Blowfish, RC5, Twofish, etc. SILC
115 does not have DES or 3DES as DES is insecure and 3DES is just too
116 slow. SILC also uses cryptographically strong random number generator
117 when it needs random numbers. Public key cryptography uses RSA
118 and Diffie Hellman algorithms. Key lengths for ciphers are initially
119 set to 128 bits but many algorithm supports longer keys. For public
120 key algorithms the starting key length is 1024 bits.
122 But the best answer for this question is that SILC is as secure as
123 its weakest link. SILC is open and the protocol is open and in public
124 thus open for security analyzes.
126 To give a list of attacks that are ineffective against SILC:
128 <li> Man-in-the-middle attacks are ineffective if proper public key
129 infrastructure is used. SILC is vulnerable to this attack if
130 the public keys used in the SILC are not verified to be trusted.
132 <li> IP spoofing is ineffective (because of encryption and trusted
135 <li> Attacks that change the contents of the data or add extra
136 data to the packets are ineffective (because of encryption and
139 <li> Passive attacks (listenning network traffic) are ineffective
140 (because of encryption). Everything is encrypted including
141 authentication data such as passwords when they are needed.
143 <li> Any sort of cryptanalytic attacks are tried to make ineffective
144 by using the best cryptographic algorithms out there.
146 <i>More to come later...</i>