Skype protocol reverse engineered, source available

Post by viraptor » Thu, Jun 02, 2011, 6:55 PM UTC

michael_dorfman wrote: post #17

_delirium wrote: post #10

Earlier quoted context omitted.

I don't believe it's possible to secure any sort of intellectual-property protection for a mere protocol. The usual way of protecting them, though, is to patent some essential feature needed to implement the protocol, which may or may not be the case here.

Actually, as I've said elsewhere, one easy way of protecting a protocol is to explicitly restrict the right to reverse engineer in in the Terms of Service of the client that implements the protocol. Without that client, there's nothing to reverse engineer.

Post by TheAmazingIdiot » Thu, Jun 02, 2011, 7:37 PM UTC

jcr wrote: post #39

dmc wrote: post #34

Earlier quoted context omitted.

What about if a developer were to now download the source code available here? Could they, in theory, develop with it as they've never attempted to reverse engineer it themselves? By using ToS, you're limiting enforcement to the people who do the RE, rather than an implementation, surely?

Actually, no. If you look at those files, you're "tainted" and can't be the one who writes a new implementation. The correct way to do reverse engineering for compatibility is to have to completely separate teams. The first does the reverse engineering and writes the specification/documentation. The second completely separate teams takes the specs/docs and writes an entirely new implementation. This is the process us…

Post by mihaelamj » Thu, Jun 02, 2011, 7:52 PM UTC

gcb wrote: post #97

So microsoft really bought skype and is already playing the bait-and-switch game?!

Post by Create » Thu, Jun 02, 2011, 8:14 PM UTC

rmc wrote: post #72

jcr wrote: post #44

I wouldn't venture to say this doesn't belong on HN since it really is interesting (if it was actually done correctly), but the files available for download are most likely illegal, were most likely created with pirated tools (IDA Pro/Hex-Rays, and yes, as a customer of theirs for over a dozen years I've reported it), and of course, the usual vilification of reverse engineering. If you're reading this on a desktop or…

The way to do reverse engineering legally is to have one team reverse engineer the target and completely document how it works. Once it's documented, another disconnected team writes a new implementation from the documentation. So you'd Skype's co-operation to do this? They are able to prevent reverse engineering by not writing the documents?

Post by jcr » Thu, Jun 02, 2011, 9:32 PM UTC

ethicalpirate wrote: post #108

jcr wrote: post #70

Earlier quoted context omitted.

I think you actually want two answers, the question you asked and "why report it?" The IDA Pro disassembler and the Hex-Rays decompiler are not only very expensive tools, but they are very difficult to purchase. Due to constant problems with piracy, these days they will only sell their products to three areas; (1) governments/law enforcement, (2) very well established corporations (typically well known security resea…

I've purchased IDA Pro for years for legitimate reversing work, but on the rare occasion that I need to do some more dodgy work for clients, where I don't want to reveal any identity (previously name, now license number) via the watermarks in the database, I will use a pirated version of the software. My point is that it is not possible to know for sure if the user of a pirated software is indeed a pirate, as there a…