The Skype Protocol Was Reverse-Engineered

One concern is perhaps best expressed in a comment to the recent LXer post 'Skype Out - Pidgin In'. This comment is in the thread 'it's the network, folks' found at http://lxer.com/module/forums/t/31803/ . It basically suggests that it may make little difference if a Skype-clone arising from this reverse-engineered code is successful or not. Microsoft-Skype managers and engineers would likely ensure that network service providers just CANNOT allow anything OTHER THAN native Skype clients to be fully functional on their networks. And eventually, these engineers WILL recognize reverse-engineered Skype-clone clients derived from this code, and disable their functionality in the name of so-called "upgrades" and "improvements".

Another concern is that Microsoft's notorious legal team may attempt to issue some type of a Cease-and-Desist order upon Efim Bushmanov, the distributor of the source-code for the reverse-engineered Skype protocol. Should a Skype-clone client derived from Bushmanov's reverse-engineered code actually prove successful, then Microsoft's legal team may then try exerting Intellectual Property theft claims against the individuals or companies developing and distributing this Skype-like client.

And eventually, these engineers WILL recognize reverse-engineered Skype-clone clients derived from this code, and disable their functionality in the name of so-called "upgrades" and "improvements".

They don't have to do anything that complicated. Just requiring a cert from the clients with M$ as the only root cert would be enough. Any non-official client connection will show up in the official clients as "suspicious". Since the official clients vastly outnumber everything else there will be little incentive for the majority of users to accommodate third-parties.

The SSL/TLS certificate infrastructure is very suspect right now, after last month's attacks made possible with stolen root certs.

There's also the fact that there are a lot of older installs, including (I believe) some embedded devices ("skype phones") that can't be easily upgraded to add a special MicroSoft(tm) Certificate Of Genuine Advantage, so such a move would shut out a chunk of the existing legitimate user-base.

> ...so such a move would shut out a chunk of the existing legitimate user-base.

When has Microsoft ever cared about that?

Yep my parents would very miffed if their Skype handset stopped working, I suspect it would be difficult to update these standalone handsets.

Their are probably quite a lot of them about, I know they were on sale nationally in the UK for quite a while via the larger electronic retail outlets, PC World, Dixons et al.

Another concern is that Microsoft's notorious legal team may attempt to issue some type of a Cease-and-Desist order upon Efim Bushmanov, the distributor of the source-code for the reverse-engineered Skype protocol.

Which would accomplish what? Judging by Efim's name, and his English skills on his blog, I'd bet that he's not a US Citizen, and with a name like that, is very likely Russian. Cease-and-desist orders in the USA don't have any effect in Russia.

then Microsoft's legal team may then try exerting Intellectual Property theft claims against the individuals or companies developing and distributing this Skype-like client.

And how are they going to enforce this? All this stuff is probably done outside the Evil Empire, so unless MS convinces the USG to put up a giant Great Firewall to keep US citizens from accessing this software, their court efforts are going to be useless. Unlike poor Dmitry, I'm sure that this Efim guy won't make the same mistake and travel here for any conferences.

The only thing MS can do is, as others have said, change the protocol to require a valid certificate from MS. However, this will break any older clients that can't be easily upgraded.