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Skype Security and Privacy Concerns
CDMA_Demo writes "Scott Granneman at Security Focus is discussing the security and privacy issues thanks to eBay's acquisition of Skype. Says the help section on Skypke's website: 'Skype uses AES (Advanced Encryption Standard), also known as Rijndael, which is used by U.S. Government organizations to protect sensitive, information. Skype uses 256-bit encryption, which has a total of 1.1 x 1077 possible keys, in order to actively encrypt the data in each Skype call or instant message. Skype uses 1024 bit RSA to negotiate symmetric AES keys. User public keys are certified by the Skype server at login using 1536 or 2048-bit RSA certificates.' Scott Granneman debates that since Skype is owned by eBay and is closed source, we have no way of verifying this claim. Further, from the article: 'At the CyberCrime 2003 conference, Joseph E. Sullivan, Director of Compliance and Law Enforcement Relations for eBay, had this to say to a group of law enforcement officials: 'I know from investigating eBay fraud cases that eBay has probably the most generous policy of any internet company when it comes to sharing information.' This raises interesting questions about how Skype and eBay together will try to avert cyber criminals from using security flaws in either system to their advantage.'"
All that new CSS and no superscripts?
[since it] is closed source, we have no way of verifying this claim
isn't that the way with all closed source software?
1184.7 keys will be hella-easy to crack... thats not too secure now is it? :P
Viable Slashdot alternatives: https://pipedot.org/ and http://soylentnews.org/
I think I can manage to brute force 1185 keys by hand, let alone with a computer. (Guess the tag didn't copy into the text input very well.)
Anm
Oh, wait...
I read Usenet for the articles.
They could make some code audit by independent security firms, but will they? (Yes, but only if they are very serius about security)
No sig for now.
Good encryption or not, I'd be more worried about the recent moves of the FCC to allow law enforcement virtual wiretap access. Our freedoms have eroded enough as of late, and it is disconcerting to say the very least. Here is the relevant link from the article and from the eff
This post has to be one of the dumbest I've ever read. Because Skype's protocol isn't public and e-Bay shares information (whatever the hell that means) there's supposed to be some specific concerns because the two are now joined? I can see either point standing on its own as a potentially interesting topic, but how does verifying whether or not a piece of software actually uses the encryption schemes it says it does and a corporate policy to share information (note that would be information that is not encrypted and intended to be shared) tie together?
What about "how eBay will try to help over-enthusiastic law enforcement deprive users of privacy"?
Nah. Could never happen in a "freedom" loving country!
you had me at #!
According to Zennström (co-founder of Kazaa and Skype) whose company skype recently got bought by eBay, Skype will still be run as a separate company by him as the head.
So I kind of doubt he'll actively be doing stuff to endanger peoples privacy.
It's worth mentioning that he left Kazaa BEFORE they became known as an adware-bloated software.
Now, that Ebay bought it I will have hard time relaying my trust to them.
Plus, federal agencies will be pressing hard to comply with CALEA and they will get what they want.
Skype as we know it, is gone...
We should all hope that Skype employees win the suit, because like it or not we're going to have to fess up when it comes time to reconsider the DCMA.
It all boils down to privacy protection; the employees and RIAA/MPAA are likely going to have a time with each other here!
Joseph E. Sullivan, Director of Compliance and Law Enforcement Relations for eBay, had this to say to a group of law enforcement officials: 'I know from investigating eBay fraud cases that eBay has probably the most generous policy of any internet company when it comes to sharing information.
Another words we help you guys out in law enforcement alot when we shouldn't so please don't step in and bother us when you should. Its a win, win we can both screw the little people at the same time.
take openssl for example. an attacker will not sit and try to break the
encryption. that is too hard. what they will do is find a bug in openssl
and own the webserver. much easier.
the fbi will simply do the same thing in a different way. why break
the encryption when a court order will get what they need?
if you really have something that needs to be kept private, you are
going to use skype? hah.
anyway, i did not bother reading the article. i just know, from the attackers
perspective, you do not pick the hardest way.
AES256 when the keys are negotiated with a 1024 bit RSA key...yeah that's really necessary.
In any case after reading TFA it seems that wasn't the author's point (slashdot descriptions misleading??, never!). Skype is insecure b/c there's no reason to trust the designers of the protocol or that the implementors got it right. And since neither is open to security reviews it's probably chalk full of side channels waiting to be discovered. And how much information do they log about user calls? That could be just as damaging.
Simple answer: don't use Skype if security is an issue. Plenty of other providers. Now that Ebay have got their hands on Skype, chances are it will be sent right downmarket anyway.
Las qué passoun
tournoun pas maï
leaving a nice big security hole
but it would of definately anoyyed you...
tee hee - sorry
Seems to me that anytime something gets too popular or mainstream the Slashdot crowd starts to turn on it. Google. Skype.
What's next? Microsoft?
This might not last for very long, as Skype's voice traffic increases. Can FCC re-qualify Skype?
BTW, do you mean that law enforcement would not be able to wiretap text-based IMs should it need that? "Hey terrorists, just use icq / aim / skype IM to share plans, the authorities aren't going to look!" -- did anybody use this rhetoric yet?
Computers make very fast, very accurate mistakes
How is it different than the PSTN? The FBI has the capability, essentially, to dial a phone number and listen in on it. They need a warrant of course, but they can easily tap phone lines.
If you depend on a communications provider to keep you data secure, espically from law enforcement, you are pretty naive. If you need to keep people out, you need to set up your own end-to-end encryption. Only then can you be sure (or at least reasonably sure) that no one is listening in. You should assume that the phone company, your ISP, their ISP, etc all can and do monitor what you do. If it is something that is important they don't see, encrypt it. Don't have them encrypt it, YOU encrypt it.
Now please don't mistake me for saying that they should monitor you, or should be allowed to, I'm not. What I'm saying is if you are doing something that is sensitive enough that if they found out it would be problematic (like financial information or something) then encrypt it.
Whenever I access servers at work, I do it via SSH, or some other similar encrypted method. Why? Well it would be a problem if someone at the ISP got the root password, they could do a lot of damage and we might never even know. They shouldn't be monitoring me like that, but it is too important to trust them with, I take it in my own hands.
I just tested it and only saw TCP port 54045 open.
I love Skypke. I wish everyone used Skypke.
Besides the security implementation... somehow a friend of mine was blocking someone from a company we were working for. This person created a conference and in the conference room appeared a message saying that for privacy settings of the user he would not be able to be added to participate. Besides of the should and shouldn't of his deeds, the skype way of privacy itself delated him and may have ended costing him his job (he was fired 1 month after the incident).
Please quote the relivant section of the Patriot act (in it's current, as passed form) along with the relivant title code info so peopel can look it up? I'm asking this in honesty, I neither believe you or disbelieve you on this, I simply want proof. I find that most people are like me and have a very poor idea what's actully covered under the Patriot act. This leads to a great deal of innacurate and sometimes outright false information about it.
So please point me to the relivant section so I can have a look myself.
When eBay acquired PayPal, eBay executives worried about long-term legal questions surrounding Internet betting. Even though it represented nearly 8% of PayPal's revenue, they decided to no longer facilitate payments for online gambling sites.
Will eBay fold under US government pressure to provide a backdoor for eavesdropping on Skype calls? Mark my words, unfortunately, "YES".
Scott Granneman debates that since Skype is owned by eBay and is closed source, we have no way of verifying this claim.
With all the talented people out there, I'm sure SOMEONE (dvd jon?) could easily test out the encryption strength. I doubt anyone would even notice if you do it to your own account and your own friends on the other side of the call.
If you're actually worried about the government listening in, 1024 bit RSA is inadequate. Adi Shamir published a paper describing a device that for $1.1 million could crack 1024 bit RSA. You can bet that the NSA has a better device than that.
In the 3 years I've been using eBay, I know of several security breaches, one of which allowed people to access an administration interface through the web, giving them access to personal information of nearly anyone using the eBay message boards [which shares login information with the main site].
I'd trust eBay with security [and PayPal with fairness] about as far as I can throw it.
Saskboy's blog is good. 9 out of 10 dentists agree.
I want the language from the act itself. I don't want to hear what someone claims it says, I want to know what it actually says. Also, according to what you linked, they do need a warrant. The standard has been lowered from what it used to be, but a warrant is still required. I know where to find the bill, same place you find all that kind of stuff, The Library of Congress, specifically their Thomas server (thomas.loc.gov). The relivant link is http://thomas.loc.gov/cgi-bin/query/z?c107:H.R.316 2: which has the bill in it's orignal forms, and as passed in to law.
What I'm asking you, since you are the claimiant, is to point to me where in there it has a "no-warrant wiretap" provision. I don't know, I admit this, I was unaware of such a provision. I wouldn't know where to look in teh act and don't feel like reading all of it. Since you claim to know of this provision, I'm asking you to show me where it is, so I can see for myself. If it is in there, it's probably somewhere in Title II.
Seems odd to use RSA to negotiate a private key. Obviously it can be implemented securely that way, but it sounds like someone chasing buzzwords.
RSA suggests that the client is preprogrammed with the server's public key, and perhaps their key-exchange involves the client making up the key, encrypting it with the servers public key and sending it to the server. In which case a trojan client might easily be made to connect to a man in the middle.
You forgot the "for varying and inconsistent values of freedom" part. ;)
One awesome way to avert cyber criminals (as well as non cyber criminals?) from using ebay and skype is to talk constantly about how willing ebay and skype are to hand over anything and everything that law enforcement asks for. I'm not even a criminal and I don't want to use ebay and skype. The plan's working!
Both, ebay and paypal have already very bad reputations. Paypal is even suspected of working with third parties on scamming people of their money. At this point I would not trust skype either. Afterall they repeatedly refused inquiries to verify the security of their proprietory protocol. Fortunately SIP has become the standard VoIP protocol and offers better quality than skype.
Does anybody know of an effort of somebody to reverse engineer the proprietary protocol? After all, they managed to do this with Kazaa.
Or is just about everybody happy with the it is (running under Linux, too) and the possibility to control it via the API?
Just wanted to know.
Cheers, Florian
Think about this: eBay now has access to personal info of Skype users. SOMEONE faxes a fake request for info from eBay and given the ease with which they give away personal info, someone's personal details from Skype are disclosed. That "SOMEONE" is the cyber criminal we are talking about! Skype's security is questionable in the first place, but now that eBay is involved, things may get worse. In case you read the article eBay can gladly hand over the following info to anyone: Of course, this just seems like another classic case of Slashdot-entitlement: "Waah, waah, I'm a criminal, I steal credit card numbers, I trade child pornography
Read the article.
Security is one of Skype's selling points. The fact that there is no way to verify it, no way to audit the code, no way to check for a back door means that you can't rely on Skype security: you just don't know. Given the background of the company and its founder, it also seems doubtful that a lot of security expertise went into the product.
And the fact that eBay has been willing to work closely with law enforcement means that they may well put in back doors even if they aren't already there.
Bottom line: if you want secure communications, don't use closed source, use something you can audit.
Yes, I find your suggestions of difficult to implement censorship offensive and was downright mortified at your choice of bold formatting in presenting it. Oh how I wish there was a way to delete it so I could never have to see anything that would make me realise other people have differing opinions and senses of humour.
For those interested to know more about the security issues associated to VoIP, you may wish to read this article. I think it's a great article as it talked about the three important aspects of VoIP security: confidentiality, availability and integrity.
w00t
Look at what Yahoo! did to the alleged Chinese "spy"—work with the Chinese government to release information posted online via Yahoo! servers. Reporters without Borders was surprised how easy it was for Shih Dao (forgive my misspelling) to be caught, but it turns out that Yahoo! handed the Chinese government information on this reporter that was widely miscited as a spy after the reporter used Yahoo!'s hosting service to report on censorship activity. Fairness and Accuracy in Reporting's radio program "Counterspin" has a report on this that is worth listening to (about 6 minutes and 40 seconds into the file). Unfortunately this is only available in proprietary and patent-encumbered formats, but perhaps it airs on a local radio station near you.
Digital Citizen
The whole article sounds like black PR to me ! GoogleTalk has NO encryption at all and is closed source too. Does that make it more private ? Everyday I see praises for Google and bad things about their compaetitors(e.g Yahoo, Skype).
Skype, sa oled surnud, ameeriklastele müümine oli lihtsalt üks väga sitt idee.
Minu kaastunne eesti tiimile, te olete tegelt lahedad kutid.
The technology export laws aren't entirely gone - we recently saw them interfering with the Spaceship One crowd trying to work with Virgin Galactic, who are Suspicious Foreigners from Great Britain.
Bill Stewart
New Fast-Compression-only CPR http://preview.tinyurl.com/dy575ks
Actually most of the keys are generated and held by the end-users (or sometimes supernodes, depending on the NAT situations), and Skype mainly holds authentication keys. That doesn't mean that there aren't major problems - you simply can't trust closed-source crypto not to leak information, typically by bad design of key-handling protocols, and it's tough enough to trust open source.
Bill Stewart
New Fast-Compression-only CPR http://preview.tinyurl.com/dy575ks
The big problem with Skype's crypto, though, is that it's closed-source and hasn't been seriously evaluated by experts - protocol design and key handling are *difficult* to do well, and it's unlikely that 128-bit vs 256-bit AES would be the weak link. For instance, some of the reverse engineering that's been done indicates that they're probably not using Diffie-Hellman for key exchange, just RSA, so they don't have perfect forward secrecy. Who knows what else they're doing wrong.
The supernode NAT avoidance system, which is what makes Skype cool and successful, is the biggest worry - too easy to get man-in-the-middle attacks there if you're not careful. A classic secure-telephony problem is that breaking crypto on wiretapped links is usually much harder than convincing the system to make a three-way conference call with the spooks.
Bill Stewart
New Fast-Compression-only CPR http://preview.tinyurl.com/dy575ks
But from a theoretical security perspective, even 512-bit RSA wouldn't be the weak link - it's likely to be key-handling or other protocol issues. How's the information handled, how's it stored, how's it refreshed, how are the random numbers generated, what leaks? Can it make a three-way conference call without telling you? Why isn't it using Diffie-Hellman for key exchange, with the RSA just for authentication? Without Adult Supervision by credible crypto professionals, you simply can't trust the stuff. The source doesn't need to be Free-As-In-Beer open, or Free-As-In-Speech open, or Accept-Patches-From-The-Public open, but it does need to have the design docs and the code reviewable by the community.
Bill Stewart
New Fast-Compression-only CPR http://preview.tinyurl.com/dy575ks
Isn't Kopete adding skype protocol support? That would allow you to check it was encrypting properly.
I am trolling
Skype is going to have trouble competing with Google Talk. I used Google Talk to talk to my brother in China today, and used Skype a few minutes later to talk to him as well. The sound quality was significantly better using Google Talk. This dispute the fact that Skype has a huge head start. In general, Skype has been around for a while and their website is still amateurish and customer service non-existance. It is absolutely impossible to get a real human at Skype to send you an email.
The only way you can ever be really sure that a piece of security software really is secure, is to read the source code.
Imagine some complete stranger comes up to you, and says he will deliver a secret message for you: if you dictate the message to him, he will write it down in a code so secret only he and his brother understand it, then send it to his brother, who will decode it and read it out to your correspondent.
Skype might be secure; it might just as probably be horrendously insecure. Without an independent audit of the source code, or a successful attempt to crack its security, we have no way to know.
{Does anyone else think it might be worth campaigning for our elected representatives to pass a law, requiring access to the source code of any software claimed as "cryptographic" or "secure" in nature?}
Je fume. Tu fumes. Nous fûmes!
The way to avoid MITM attacks with DH is to digitally sign the parts of the key exchange, which you typically do with RSA or the ElGamal signature algorithms. There are other ways to do it - have each side read the other a fingerprint of the key they're using, but you can't automate that (or a MITM could fake it), so it's not really practical for everyday conversations, as opposed to using it for military security or something. Diffie likes the signed DH approach.
In RSA, the way you avoid MITM attacks is to make sure you've really got the other person's public key, which you typically do by using a Public Key Infrastructure or else by handing them the key on some other channel, such as printing a hash of the key on your business card. Skype does some keyserver stuff to automate this. But you're still vulnerable to somebody getting the private key later and being able to read all conversations they've wiretapped in the past.
Bill Stewart
New Fast-Compression-only CPR http://preview.tinyurl.com/dy575ks
As security experts, I would find fault with telling the world this much about any security system. The first error here is letting this much information out at all because it narrows down the possibilites. The fact that this can not be confirmed is irrelevant. Any security system should NOT be able to be confirmed by the public, including public source. Make it as hard to crack as possible and keep it as secret as possible. Asking for any security system to be confirmed or confirmable is not only ridiculous but also harmful to real security experts who know better. 'Skype uses AES (Advanced Encryption Standard), also known as Rijndael, which is used by U.S. Government organizations to protect sensitive, information. Skype uses 256-bit encryption, which has a total of 1.1 x 1077 possible keys, in order to actively encrypt the data in each Skype call or instant message. Skype uses 1024 bit RSA to negotiate symmetric AES keys. User public keys are certified by the Skype server at login using 1536 or 2048-bit RSA certificates.'
The rest of the threads are mere ego centric fightings.
The bottom line is, "It connects two computers or one computer and a phone [and hopefully a phone to phone in future, which is just SkypeIn+SkypeOut, and proabibly this is what interests eBay: getting face to face with the Telecoms] to chat with an excellent quality of sound for free or for very cheap rates".