Frequently Asked Questions
Q: What is SILC?
A: SILC (Secure Internet Live Conferencing) is a protocol which provides
secure conferencing services in the Internet over insecure channel.
SILC is IRC like although internally they are very different. Biggest
similiarity between SILC and IRC is that they both provide conferencing
services and that SILC has almost same commands as IRC. Other than
that they are nothing alike.
Biggest differences are that SILC is secure what IRC is not in any
way. The network model is also entirely different compared to IRC.
Q: Why SILC in the first place?
A: Simply for fun, nothing more. An actually for need back then when
it was started. SILC has been very interesting and educational
project.
Q: When will SILC be completed?
A: SILC still has a lot things to do. The time of completion is much
related to how many interested people is willing to join the effort.
It will be ready when it is ready. The reason for release of the
current development version is just to get it out and people aware
that something like this exist. SILC is not ready for production
use so it is not expected that there is that much of a hype around
SILC. I don't have to hurry... :)
Q: Why use SILC? Why not IRC with SSL?
A: Sure, that is possible, although, does that secure the entire IRC
network? And does that increase or decrease the lags and splits in
the IRC network? Does that provide user based security where some
specific private message are secured.? Does that provide security
where some specific channel messages are secured? Security is not
just about applying encryption to traffic and SILC is not just about
`encrypting the traffic`. You cannot make insecure protocol suddenly
secure just by encrypting the traffic. SILC is not meant to be IRC
replacement. IRC is good for some things, SILC is good for same and
some other things.
Q: Can I use SILC with IRC client? What about can I use IRC with SILC
client?
A: Answer for both question is no. IRC client is in no way compatible
with SILC server. SILC client cannot currently use IRC but this may
change in the future if IRC support is added to the SILC client.
After that one could use both SILC and IRC with the same client.
Although, even then one cannot talk from SILC network to IRC network.
That just is not possible.
Q: Why SILC? Why not IRC3?
A: Question that is justified no doubt of that. I didn't start doing SILC
to be replacement for IRC. SILC was something that didn't exist in
1996 or even today except that SILC is now released. However, I did
check out the IRC3 project in 1997 when I started coding and planning
the SILC protocol.
But, IRC3 is problematic. Why? Because it still doesn't exist. The
project is at the same spot where it was in 1997 when I checked it out.
And it was old project back then as well. Couple of months ago I
checked it again and nothing were happening. That's the problem of IRC3
project. The same almost happened to SILC as well as I wasn't making
real progress over the years. I talked to the original author of IRC,
Jarkko Oikarinen, in 1997 and he directed me to the IRC3 project,
although he said that IRC3 is a lot of talking and not that much of
anything else. I am not trying to put down the IRC3 project but its
problem is that no one in the project is able to make a decision what
is the best way to go about making the IRC3 and I wasn't going to be
part of that. The fact is that if I would've gone to IRC3 project,
nor IRC3 or SILC would exist today. I think IRC3 could be something
really great if they just would get their act together and start
coding the thing.
Q: How secure SILC really is?
A: A good question which I don't have a answer. SILC has been tried to
make as secure as possible. However, there is no security protocol
or security software that has not been vulnerable to some sort of
attacks. SILC is in no means different from this. So, it is suspected
that there are security holes in the SILC. These holes just needs to
be found so that they can be fixed.
But to give you some parameters of security SILC uses the most secure
crytographic algorithms such as Blowfish, RC5, Twofish, etc. SILC
does not have DES or 3DES as DES is insecure and 3DES is just too
slow. SILC also uses cryptographically strong random number generator
when it needs random numbers. Public key cryptography uses RSA
and Diffie Hellman algorithms. Key lengths for ciphers are initially
set to 128 bits but many algorithm supports longer keys. For public
key algorithms the starting key length is 1024 bits.
But the best answer for this question is that SILC is as secure as
its weakest link. SILC is open and the protocol is open and in public
thus open for security analyzes.
To give a list of attacks that are ineffective against SILC:
Man-in-the-middle attacks are ineffective if proper public key
infrastructure is used. SILC is vulnerable to this attack if
the public keys used in the SILC are not verified to be trusted.
IP spoofing is ineffective (because of encryption and trusted
keys).
Attacks that change the contents of the data or add extra
data to the packets are ineffective (because of encryption and
integrity checks).
Passive attacks (listenning network traffic) are ineffective
(because of encryption). Everything is encrypted including
authentication data such as passwords when they are needed.
Any sort of cryptanalytic attacks are tried to make ineffective
by using the best cryptographic algorithms out there.
More to come later...