The "Oyster card" used on the London Tube was at issue in the Dutch case, and a similar fare card used on the Boston "T" was the center of the U.S. case. The Dutch court got it right, and the American court, in Boston, got it wrong from the start -- despite facing an open-and-shut case of First Amendment prior restraint.

The U.S. court has since seen the error of its ways -- but the damage is done. The MIT security researchers who were prepared to discuss their Boston findings at the DefCon security conference were prevented from giving their talk.

The ethics of full disclosure are intimately familiar to those of us in the computer-security field. Before full disclosure became the norm, researchers would quietly disclose vulnerabilities to the vendors -- who would routinely ignore them. Sometimes vendors would even threaten researchers with legal action if they disclosed the vulnerabilities.

Later on, researchers started disclosing the existence of a vulnerability but not the details. Vendors responded by denying the security holes' existence, or calling them just theoretical. It wasn't until full disclosure became the norm that vendors began consistently fixing vulnerabilities quickly. Now that vendors routinely patch vulnerabilities, researchers generally give them advance notice to allow them to patch their systems before the vulnerability is published. But even with this "responsible disclosure" protocol, it's the threat of disclosure that motivates them to patch their systems. Full disclosure is the mechanism (.pdf) by which computer security improves.

Outside of computer security, secrecy is much more the norm. Some security communities, like locksmiths, behave much like medieval guilds, divulging the secrets of their profession only to those within it. These communities hate open research, and have responded with surprising vitriol to researchers who have found serious vulnerabilities in bicycle locks, combination safes (.pdf), master-key systems and many other security devices.

Researchers have received a similar reaction from other communities more used to secrecy than openness. Researchers -- sometimes young students -- who discovered and published flaws in copyright-protection schemes, voting-machine security and now wireless access cards have all suffered recriminations and sometimes lawsuits for not keeping the vulnerabilities secret. When Christopher Soghoian created a website allowing people to print fake airline boarding passes, he got several unpleasant visits from the FBI.

This preference for secrecy comes from confusing a vulnerability with information about that vulnerability. Using secrecy as a security measure is fundamentally fragile. It assumes that the bad guys don't do their own security research. It assumes that no one else will find the same vulnerability. It assumes that information won't leak out even if the research results are suppressed. These assumptions are all incorrect.

The problem isn't the researchers; it's the products themselves. Companies will only design security as good as what their customers know to ask for. Full disclosure helps customers evaluate the security of the products they buy, and educates them in how to ask for better security. The Dutch court got it exactly right when it wrote: "Damage to NXP is not the result of the publication of the article but of the production and sale of a chip that appears to have shortcomings."

In a world of forced secrecy, vendors make inflated claims about their products, vulnerabilities don't get fixed, and customers are no wiser. Security research is stifled, and security technology doesn't improve. The only beneficiaries are the bad guys.

If you'll forgive the analogy, the ethics of full disclosure parallel the ethics of not paying kidnapping ransoms. We all know why we don't pay kidnappers: It encourages more kidnappings. Yet in every kidnapping case, there's someone -- a spouse, a parent, an employer -- with a good reason why, in this one case, we should make an exception.

The reason we want researchers to publish vulnerabilities is because that's how security improves. But in every case there's someone -- the Massachusetts Bay Transit Authority, the locksmiths, an election machine manufacturer -- who argues that, in this one case, we should make an exception.

We shouldn't. The benefits of responsibly publishing attacks greatly outweigh the potential harm. Disclosure encourages companies to build security properly rather than relying on shoddy design and secrecy, and discourages them from promising security based on their ability to threaten researchers. It's how we learn about security, and how we improve future security.

This essay previously appeared on Wired.com.

EDITED TO ADD (8/26): Matt Blaze has a good essay on the topic.

The "Oyster card" used on the London Tube was at issue in the Dutch case, and a similar fare card used on the Boston "T" was the center of the U.S. case. The Dutch court got it right, and the American court, in Boston, got it wrong from the start -- despite facing an open-and-shut case of First Amendment prior restraint.

The U.S. court has since seen the error of its ways -- but the damage is done. The MIT security researchers who were prepared to discuss their Boston findings at the DefCon security conference were prevented from giving their talk.

The ethics of full disclosure are intimately familiar to those of us in the computer-security field. Before full disclosure became the norm, researchers would quietly disclose vulnerabilities to the vendors -- who would routinely ignore them. Sometimes vendors would even threaten researchers with legal action if they disclosed the vulnerabilities.

Later on, researchers started disclosing the existence of a vulnerability but not the details. Vendors responded by denying the security holes' existence, or calling them just theoretical. It wasn't until full disclosure became the norm that vendors began consistently fixing vulnerabilities quickly. Now that vendors routinely patch vulnerabilities, researchers generally give them advance notice to allow them to patch their systems before the vulnerability is published. But even with this "responsible disclosure" protocol, it's the threat of disclosure that motivates them to patch their systems. Full disclosure is the mechanism (.pdf) by which computer security improves.

Outside of computer security, secrecy is much more the norm. Some security communities, like locksmiths, behave much like medieval guilds, divulging the secrets of their profession only to those within it. These communities hate open research, and have responded with surprising vitriol to researchers who have found serious vulnerabilities in bicycle locks, combination safes (.pdf), master-key systems and many other security devices.

Researchers have received a similar reaction from other communities more used to secrecy than openness. Researchers -- sometimes young students -- who discovered and published flaws in copyright-protection schemes, voting-machine security and now wireless access cards have all suffered recriminations and sometimes lawsuits for not keeping the vulnerabilities secret. When Christopher Soghoian created a website allowing people to print fake airline boarding passes, he got several unpleasant visits from the FBI.

This preference for secrecy comes from confusing a vulnerability with information about that vulnerability. Using secrecy as a security measure is fundamentally fragile. It assumes that the bad guys don't do their own security research. It assumes that no one else will find the same vulnerability. It assumes that information won't leak out even if the research results are suppressed. These assumptions are all incorrect.

The problem isn't the researchers; it's the products themselves. Companies will only design security as good as what their customers know to ask for. Full disclosure helps customers evaluate the security of the products they buy, and educates them in how to ask for better security. The Dutch court got it exactly right when it wrote: "Damage to NXP is not the result of the publication of the article but of the production and sale of a chip that appears to have shortcomings."

In a world of forced secrecy, vendors make inflated claims about their products, vulnerabilities don't get fixed, and customers are no wiser. Security research is stifled, and security technology doesn't improve. The only beneficiaries are the bad guys.

If you'll forgive the analogy, the ethics of full disclosure parallel the ethics of not paying kidnapping ransoms. We all know why we don't pay kidnappers: It encourages more kidnappings. Yet in every kidnapping case, there's someone -- a spouse, a parent, an employer -- with a good reason why, in this one case, we should make an exception.

The reason we want researchers to publish vulnerabilities is because that's how security improves. But in every case there's someone -- the Massachusetts Bay Transit Authority, the locksmiths, an election machine manufacturer -- who argues that, in this one case, we should make an exception.

We shouldn't. The benefits of responsibly publishing attacks greatly outweigh the potential harm. Disclosure encourages companies to build security properly rather than relying on shoddy design and secrecy, and discourages them from promising security based on their ability to threaten researchers. It's how we learn about security, and how we improve future security.

---

Bruce Schneier is Chief Security Technology Officer of BT Global Services and author of Beyond Fear: Thinking Sensibly About Security in an Uncertain World. You can read more of his writings on his website.

You will discern a certain amount of enthusiasm for blocking, and for a “something must be done” approach. However, in coming to their conclusions, they do not, in my view, seem to have listened too hard to the evidence, or sought out expertise elsewhere in the world…

Google/YouTube told them that 10 hours of video was posted every minute, and the amount is increasing. In the oral evidence session an MP helpfully suggested: “That video content is tagged. You do not need to look at every single minute of video content. Surely you could have people who would look at the video content which is tagged with labels which suggest it could be inappropriate.” Of course “happy_slapping.wmv” or “fluffy_bunnies.avi” must always contain exactly what it says on the tin (not!) but unaccountably Google said it was a “fair suggestion”, so perhaps my cynicism is misplaced.

However, back to blocking.

I submitted some evidence of my own, which the committee summarised, reasonably accurately:

Dr Richard Clayton, a researcher in the Security Group of the Computer Laboratory at Cambridge University and author of several academic papers on methods for blocking access to Internet content, pointed out that there was no single blocking method which was both inexpensive and discerning enough to block access to only one part of a large website (such as FaceBook). In his view, the fatal flaw of all network-level blocking schemes was the ease with which they could be overcome, either by encrypting content or by the use of proxy services hosted outside the UK.

The committee’s conclusion, having read this was:

At a time of rapid technological change, it is difficult to judge whether blocking access to Internet content at network level by Internet service providers is likely to become ineffective in the near future. However, this is not a reason for not doing so while it is still effective for the overwhelming majority of users.

which I suppose logically means that the committee thinks that blocking should now be discarded as a policy option — but somehow I think that isn’t their intended meaning.

The Committee should perhaps have a look at this Australian report, which found that ISP level content filtering (and in Australia the politicians want to use ISP level filtering to provide a child-friendly Internet) did work (up to a point) at Tier 3 (the smallest) ISPs. The up-to-a-point is that unlike previous tests the systems didn’t completely wreck the browsing experience by slowing it down. However, the systems blocked only 85-98% of illegal material and similar percentages of material suitable for adults but not for younger children. Interestingly some products were better at different categories.

Getting that many sites wrong is really quite significant, so it’s difficult to see this as a ringing endorsement for blocking the web. Additionally, the Australian report found that the blocking was useless on “non-web” protocols (such as peer-to-peer) and their report specifically didn’t consider cost, or ease of circumvention — so it’s not just UK politicians not wanting to consider evidence on that topic!

Finally, I should note that the Culture Media and Sport Committee has also ignored some rather more recent academic work. The MPs have put into their report that they were horrified to discover that child sexual abuse images took 24 hours to remove in the UK. What (should they ever learn of it) will they make of the recent discovery by Tyler Moore and myself that shows that if the website is hosted abroad then a month is more to be expected?

If someone is simultaneously watching a user’s traffic as it enters and leaves the network, it is possible to de-anonymise the communication. This could occur if the first and last node for a connection is controlled by the same person. Tor takes some steps to avoid this possibility e.g. no two computers on the same /16 network may be chosen for each connection. However, someone with access to several networks could circumvent this measure.

Not only is route selection critical for security, but it’s also a significant performance factor. Tor nodes vary dramatically in their capacity, mainly due to their network connections. If all nodes were chosen with equal likelihood, the slower ones would cripple the network. This is why Tor weights the selection probability for a node proportional to its contribution to the network bandwidth.

Because of the dual importance of route selection, there are a number of proposals which offer an alternative to Tor’s bandwidth-weighted algorithm. Later this week at PETS I’ll be presenting my paper, co-authored with Robert N.M. Watson, “Metrics for security and performance in low-latency anonymity systems”. In this paper, we examine several route selection algorithms and evaluate their security and performance.

Intuitively, a route selection algorithm which weights all nodes equally appears the most secure because an attacker can’t make their node count any more than the others. This has been formalized by two measures: Gini coefficient and entropy. In fact the reality is more complex — uniform node selection resists attackers with lots of bandwidth, whereas bandwidth-weighting is better against attackers with lots of nodes.

Our paper explores the probability of path compromise of different route selection algorithms, when under attack by a range of different adversaries. We find that none of the proposals are optimal against all adversaries, and so summarizing effective security in terms of a single figure is not feasible. We also model the performance of the schemes and show that bandwidth-weighting offers both low latency and high resistance to attack by bandwidth-constrained adversaries.

With all this talk and reporting about security concerns, lets change the channel for a moment and assess the potential security benefits of Cloud Computing.

In my view, there are some strong technical security arguments in favour of Cloud Computing - assuming we can find ways to manage the risks.

With this new paradigm come challenges and opportunities.  The challenges are getting plenty of attention - I’m regularly afforded the opportunity to comment on them, plus obviously I cover them on this blog.  However, lets not lose sight of the potential upside.

In this post, I walk through seven technical security benefits.  Some are immediate, others may arise over time and have conditions attached (some unstated for the sake of brevity).  However, I’m including the longer-range benefits now to raise awareness.  Some of the outcomes listed are available today without the Cloud, but they are either complex and slow to implement (and thus less likely to happen) or prohibitive for capital cost reasons.  I don’t claim this is a definitive list - it reflects where my thinking is today.

Some benefits depend on the Cloud service used and therefore do not apply across the board.  For example; I see no solid forensic benefits with SaaS.  Also, for space reasons, I’m purposely not including the ‘flip side’ to these benefits, however if you read this blog regularly you should recognise some.

On a sidenote, I believe the Cloud offers Small and Medium Businesses major potential security benefits.  Frequently SMBs struggle with limited or non-existent in-house INFOSEC resources and budgets.  The caveat is that the Cloud market is still very new - security offerings are somewhat foggy - making selection tricky.  Clearly, not all Cloud providers will offer the same security.

Seven Technical Security Benefits of the Cloud

1. Centralised Data

• Reduced Data Leakage: this is the benefit I hear most from Cloud providers - and in my view they are right.  How many laptops do we need to lose before we get this?  How many backup tapes?  The data “landmines” of today could be greatly reduced by the Cloud as thin client technology becomes prevalent.  Small, temporary caches on handheld devices or Netbook computers pose less risk than transporting data buckets in the form of laptops.  Ask the CISO of any large company if all laptops have company ‘mandated’ controls consistently applied; e.g. full disk encryption.  You’ll see the answer by looking at the whites of their eyes.  Despite best efforts around asset management and endpoint security we continue to see embarrassing and disturbing misses.  And what about SMBs?  How many use encryption for sensitive data, or even have a data classification policy in place?
• Monitoring benefits: central storage is easier to control and monitor.  The flipside is the nightmare scenario of comprehensive data theft.  However, I would rather spend my time as a security professional figuring out smart ways to protect and monitor access to data stored in one place (with the benefit of situational advantage) than trying to figure out all the places where the company data resides across a myriad of thick clients!  You can get the benefits of Thin Clients today but Cloud Storage provides a way to centralise the data faster and potentially cheaper.  The logistical challenge today is getting Terabytes of data to the Cloud in the first place.

2. Incident Response / Forensics

• Forensic readiness: with Infrastructure as a Service (IaaS) providers, I can build a dedicated forensic server in the same Cloud as my company and place it offline, ready for use when needed.  I would only need pay for storage until an incident happens and I need to bring it online.  I don’t need to call someone to bring it online or install some kind of remote boot software - I just click a button in the Cloud Providers web interface.  If I have multiple incident responders, I can give them a copy of the VM so we can distribute the forensic workload based on the job at hand or as new sources of evidence arise and need analysis.  To fully realise this benefit, commercial forensic software vendors would need to move away from archaic, physical dongle based licensing schemes to a network licensing model.
• Decrease evidence acquisition time: if a server in the Cloud gets compromised (i.e. broken into), I can now clone that server at the click of a mouse and make the cloned disks instantly available to my Cloud Forensics server.  I didn’t need to “find” storage or have it “ready, waiting and unused” - its just there.
• Eliminate or reduce service downtime: Note that in the above scenario I didn’t have to go tell the COO that the system needs to be taken offline for hours whilst I dig around in the RAID Array hoping that my physical acqusition toolkit is compatible (and that the version of RAID firmware isn’t supported by my forensic software).  Abstracting the hardware removes a barrier to even doing forensics in some situations.
• Decrease evidence transfer time: In the same Cloud, bit fot bit copies are super fast - made faster by that replicated, distributed filesystem my Cloud provider engineered for me.  From a network traffic perspective, it may even be free to make the copy in the same Cloud.  Without the Cloud, I would have to a lot of time consuming and expensive provisioning of physical devices.  I only pay for the storage as long as I need the evidence.
• Eliminate forensic image verification time: Some Cloud Storage implementations expose a cryptographic checksum or hash.  For example, Amazon S3 generates an MD5 hash automagically when you store an object.  In theory you no longer need to generate time-consuming MD5 checksums using external tools - its already there.
• Decrease time to access protected documents: Immense CPU power opens some doors.  Did the suspect password protect a document that is relevant to the investigation?  You can now test a wider range of candidate passwords in less time to speed investigations.

3. Password assurance testing (aka cracking)

• Decrease password cracking time: if your organisation regularly tests password strength by running password crackers you can use Cloud Compute to decrease crack time and you only pay for what you use.  Ironically, your cracking costs go up as people choose better passwords ;-).
• Keep cracking activities to dedicated machines: if today you use a distributed password cracker to spread the load across non-production machines, you can now put those agents in dedicated Compute instances - and thus stop mixing sensitive credentials with other workloads.

4. Logging

• “Unlimited”, pay per drink storage: logging is often an afterthought, consequently insufficient disk space is allocated and logging is either non-existant or minimal.  Cloud Storage changes all this - no more ‘guessing’ how much storage you need for standard logs.
• Improve log indexing and search: with your logs in the Cloud you can leverage Cloud Compute to index those logs in real-time and get the benefit of instant search results. What is different here?  The Compute instances can be plumbed in and scale as needed based on the logging load - meaning a true real-time view.
• Getting compliant with Extended logging: most modern operating systems offer extended logging in the form of a C2 audit trail.  This is rarely enabled for fear of performance degradation and log size.  Now you can ‘opt-in’ easily - if you are willing to pay for the enhanced logging, you can do so.  Granular logging makes compliance and investigations easier.

5. Improve the state of security software (performance)

• Drive vendors to create more efficient security software: Billable CPU cycles get noticed.  More attention will be paid to inefficient processes; e.g. poorly tuned security agents.  Process accounting will make a comeback as customers target ‘expensive’ processes.  Security vendors that understand how to squeeze the most performance from their software will win.

6. Secure builds

• Pre-hardened, change control builds: this is primarily a benefit of virtualization based Cloud Computing.  Now you get a chance to start ’secure’ (by your own definition) - you create your Gold Image VM and clone away.  There are ways to do this today with bare-metal OS installs but frequently these require additional 3rd party tools, are time consuming to clone or add yet another agent to each endpoint.
• Reduce exposure through patching offline: Gold images can be kept up securely kept up to date.  Offline VMs can be conveniently patched “off” the network.
• Easier to test impact of security changes: this is a big one.  Spin up a copy of your production environment, implement a security change and test the impact at low cost, with minimal startup time.  This is a big deal and removes a major barrier to ‘doing’ security in production environments.

7. Security Testing

• Reduce cost of testing security: a SaaS provider only passes on a portion of their security testing costs.  By sharing the same application as a service, you don’t foot the expensive security code review and/or penetration test.  Even with Platform as a Service (PaaS) where your developers get to write code, there are potential cost economies of scale (particularly around use of code scanning tools that sweep source code for security weaknesses).

Your Thoughts?

What benefits do you see that I haven’t included in the above list?  Where do you agree/disagree and importantly, why?

Even worse is that the emails sent by banks often resemble phishing attempts, and sometimes directly violate the advice given to customers. With this “do as I say, not as I do” approach, it is no surprise that customers regularly fall for the scams. In fact, sometimes a legitimate email look so fake that the bank's own security staff think it's a phish.

And it's not just banks which are slipping up. I received an email from Paypal, asking users to “click here and enter your password” despite the warning on the same page: “PayPal will never ask you to enter your password in an email”. What can customers be reasonably expected to do, given this type of training? I simply closed my account.

Email is a valuable sales channel for banks, and marketing teams evidently have not being willing to sacrifice it, despite the (justified) concerns of the security departments. This fact, coupled with the weak authentication schemes currently deployed, makes life for fraudsters easy. Paypal have tried one alternative approach – a two-factor token – but these are still vulnerable to attack. Strong security solutions, accepted both by customers and marketing, are needed to mitigate the large damages from fraud we see today.