Privacy@Google

While responding to concerns about privacy of those who use Google's services Eric Schmidt said that users worried about privacy can choose not to use Google's services. Not only does this response reflect sheer hubris on his part and alienate intelligent beings, it also sidesteps the real question "Should users of Google be worried about privacy?". Privacy international says YES.

Privacy international findings are here: http://www.privacyinternational.org/issues/internet/interimrankings.pdf





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security research, rootkits and TPM

The recent highlight on security research has encouraged a lot of "security researchers" (although the term is a bit too generic...these people are actually "vulnerability researchers"). Today's software contains a lot of security bugs and these researchers find a lot of them. It is a good thing...it helps raise awareness of the problem and pushes the software vendors to fix these bugs.
The media limelight on these researchers also encourages "publicity stunts" and other "celebrity wars". Here is an example:
http://www.securityfocus.com/brief/537
http://www.matasano.com/log/895/joanna-we-can-detect-bluepill-let-us-prove-it/

I do believe that "theoretically" it is impossible to write an undetectable rootkit if the detection system is allowed access to the external world (network access is usually good enough). However, "practically" it is a contest between the rootkit engineer and the rootkit detector engineer. It is certainly possible although difficult to create a rootkit that will be very hard to detect. Similarly, it is possible but difficult to engineer a rootkit detector good enough to detect this rootkit.

Trusted Platform Module is a promising technology that might render the issue moot in the long run. However, TPM itself may have bugs in the beginning: http://www.networkworld.com/news/2007/062707-black-hat.html
I don't know why these guys withdrew...was it because they had found no exploits or were silenced by the TCG?

TPM may have some vulnerabilities in its specification and implementations of the specification will certainly have more. It is still a good technology because in a world with TPM bugs will be confined to a small area and therefore could be more easily found and fixed than in a world without TPM.



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What is a Host IPS?

The term Host IPS is used mostly to denote endpoint software that monitors execution of applications and looks for intrusions. Interestingly, the term Host IPS implies the absence of signatures whereas the term network IPS generally implies the presence of them :) Of course, Host IPS is generally supposed to complement signature based anti-virus and contemporary network IPS's utilize more techniques in addition to signatures.

Most host IPS's use a mix of the following techniques to monitor program execution (sometimes called program "behavior"):
- intercept system calls
- intercept access to resources like registry, file system, libraries(DLLs)
- track origin of the code being executed
- execute the program in a sandbox...the extreme case is interpreting the program instruction by instruction instead of running it directly on the processor.

There are several compile time tools for making the stack difficult to overflow. These defend(not foolproof) against buffer overflows on a stack:
- stack guard
- stack shield
- stack ghost

...and a run time method
- program shepherding

Some commercially available Host IPS products are:
- McFee
- Cisco
- Symantec
- Determina



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Methods for network based devices implementing data leak prevention

I wrote about data leaks before . A painful problem like this is an opportunity for some and we now have quite a few startups selling products to monitor data leaving a company's network for sensitive information. Vontu and Reconnex are a couple of them. Port Authority was another that was acquired by WebSense.
It is interesting to see how one can go about solving this problem. [Note: In this writeup I focus only on detecting leaks through the company's network. There is another ways in which information can be leaked: through storage devices like hard disks and USB flash. The techniques I mention here do not work for them.]
First we need to define sensitive data. A few items like social security numbers can be easily defined as regular expressions (ddd-dd-dddd, where d is a digit) and one can scan all network data for anything that looks like a social security number. But what about other information? We can apply the pattern matching approach to other structured information like patient records in a healthcare facility, account information in a bank etc. What about unstructured information like design documents or patent ideas communicated between team members in emails? It does not follow a pre-defined pattern. Is there a way of monitoring it? Fortunately, there is. One method is to use rabin fingerprints . Calculate these fingerprints for all potentially sensitive data and match it with the fingerprints calculated for network traffic. This method works well because even if the data was changed a little (like a section from a document was copy-pasted into an email etc) it is matched by the fingerprints.
An approach that combines pattern matching for known and/or structured data and fingerprinting for unstructured data works well in detecting unintended accidental data leaks in information passing through a company's network. A report says that 60% of the leaks reported so far are of this nature. So it is a useful approach. What about the other 40% intentional data theft? I will write about it another day but the first thing that will come into mind is to apply some kind of "locks" and "alarms". Locks in the digital world are cryptographic techniques and alarms are data access, modification and transmission logs.

[Some readers will note that I did not mention "watermarks". I consider that as a subset of structured data]




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Sandboxes for false positives in IDS

Signatures have been an effective but not exhaustive method for threat prevention for a long time. In the early days there were issues with false postives, then there were shortcomings in dealing with polymorphic threats but these were due to "bad signatures" and sometimes performance tradeoffs. That is no longer true [I wrote about various IDS algorithms before]
However, as I said it is not an exhaustive method so it is often complemented by protocol anomaly detection and behavioral anomaly detection. Protocol anomaly detection(PAD) is a very reliable technique but a mere presence of an anomaly does not always indicate an intrusion. Behavioral anomaly detection(NBAD) is worse because it relies on unproven statistical models of network traffic and user behaviour. [Related reading ]. However, both of these methods are useful in locating "suspicious activity", protocol anomaly detection more so than behavioral. The challenge is to deal with the false positives they inevitably result in. A good solution to this problem is now available in atleast two commercial products: FireEye and CheckPoint's MCP which use "sandbox execution" of code extracted from anomalous traffic. The approach is in its infancy but is very promising because it is to intrusion detection what "blood tests"are to disease diagnosis. It has very low false positives and works against zero day threats. It is "expensive" because it requires a lot of computation if PAD and NBAD are used to narrow the search space of traffic, it can scale well.
I believe most commercial IDS/IPS and even anti-virus/spyware vendors will add this weapon to their arsenal this year. Thoughts?



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Personal information leaks...

I came across this news item http://news.yahoo.com/s/ap/20070213/ap_on_re_us/security_breach;_ylt=AmTRfUWSmPQsOMV3KG7fmoAEtbAF
about VA losing data again, not reporting it quickly and making a completely useless but misleading remark while doing so: "...it doesn't have any reason to believe anyone has misused data...The agency offered a year of free credit monitoring to anyone whose information is compromised". Useless because if the information was misused VA won't be the first to know and if they did eventually learn that the information is misused they may take another 3 weeks to report it. Perhaps the motivation behind an announcement like this is that it may deter the miscreants from mischief for a year. The other comtemporary data leak (TJ Maxx) has shown that this is not true.
Misleading because they are offering 1 year free credit reporting which may give a false sense of security to those customers who use that service. Armed with the SSN and other sensitive information the miscreants can carry out their ill intents after a year. Also some of the mischief they do may not get into the credit report at all and the part which does will take a while before it does show up and at that time it might be too late (e.g. money is transferred to Bahamas etc. and nothing can be done now)

I have blogged about the problems of using SSNs and other "permanent" and personal information for authentication here http://securetheworld.blogspot.com/2007/01/social-security-numbers-as.html





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Microsoft's trusted ecosystem vision and its review at Dark Reading...

One of the technologies Bill Gates mentioned as part of Microsoft’s “trust ecosystem” was IPSec. [http://www.microsoft.com/presspass/exec/billg/speeches/2006/02-14RSA06.mspx ]. Tim Wilson at Dark Reading believes that it is an unproven technology ;) and SSL is better. I would like to point out to him that IPSec has been around for a very long time and there are hundreds of good products around. The only reason why SSL became more popular as a VPN method in recent years is because web browsers have it builtin and a lot of applications people were interested in were web based. If Microsoft had provided an easy to use IPSec client in Windows from the beginning it could have been different. As far as core technology is concerned there is both IPSec and SSL use pretty much the same cryptographic algorithms and therefore are equally secure. Since it runs at the network layer IPSec can support almost all applications while SSL is restricted to those that use TCP. While that covers a lot of applications, it does not cover VoIP which uses UDP. In addition IPSec scales well as it does not require the device to terminate TCP. It allows multiple sessions on a single channel resulting in better scalability in terms of the number of concurrent channels a VPN terminating device has to support and the number of key exchanges that need to be done.
Tim claims that IPSec is insecure because it connects the endpoint to the whole network whereas SSL connects it to only a specific application. While there is some truth to this, IPSec VPN devices generally allow policies to be configured that can restrict access to specific applications.
One of the new frontiers in the security war is the internal corporate network. To secure them one of the things that need to be done is to authenticate endpoints connecting to it and enforce policies. This is being done by NAC (pre and post admission) but the authentication aspect is insecure today because in the absence of a cryptographically secured connection, endpoints can spoof their addresses and fool the NAC devices. I believe IPSec holds promise as a standard and proven technology to fix this problem. I am glad that Microsoft is thinking about this and if they integrate IPSec with 802.1x into Windows seamlessly, it will encourage switch vendors to add IPSec termination to switches and secure the corporate LAN.




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