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