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