Tag Archives: BitTorrent

Internet Security, Security

Howto: Share Files Securely/Privately

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Background

The joint concepts of Secure and Private are relative and subjective. Relative in that there are very few absolutes, but there are an infinite number of variations that may be better or worse. Qualifying “better or worse” is where the subjective comes into play. It is subjective in terms of who / what you are trying protect your files from. Is it your family, co-workers, your neighbors, the Internet, some large corporation trying to characterize you (in order to better sell to you), or the government? Depending on how good of a solution and who you are trying to protect your privacy from, we can look at a few easy (and practical) solutions.

Off the Shelf

There are off the shelf solutions that provide file sharing options. Dropbox, Box and Google Drive are three popular examples or cloud storage solutions – meaning your files are on their servers. Each one of these provides some degree of privacy / security. Each of these services use a username / password to restrict access, and additionally Google and Dropbox support two factor authentication using Google Authenticator. Each of these services uses SSL/TLS to provide a secure channel from the client to their servers. What they do not provide is any explicit privacy or security from the respective services or anybody with a NSL.

Fundamentally these services are not particularly private, secure, but they do provide some degree of security / privacy. If you use them and Two Factor Authentication is an option – use it.

A Better Option(s)

If the convenience of these services is appealing, but you have some real need for something more secure, we have a better solution. TrueCrypt is an disk encryption tool that can create secure containers for files. Specifically, Truecrypt can be used to create a secure file container in your GDrive/Dropbox/Box sync directory on your client system. This container can be opened by Truecrypt, files placed inside, and then be closed – at which point the service will sync the file up to their servers. They services will have access to the file, but its contents will be completely hidden from all except the keyholder. Note – a large container will hold lots of files, but the entire file will need to be synced even if there is a minor change – so consider wisely how large / small this container should be.

Another tool is Keepass, a secure password locker that is similar – but only for password / account information. Both of these tools are also cross platform and open source.

An Even Better Option

One of the core flaws with each of these cloud storage solutions identified above (as examples) is that ultimately all of your data resides on their servers within the providers data centers. BitTorrent Sync is a solution that breaks that paradigm by distributing files using the bittorrent protocols in a peer to peer (P2P) fashion. The result is that files can be distributed and shared between multiple users / platforms, but they do not exist on any cloud server – greatly reducing the risk of compromise-ever. BitTorrent Sync is easy to setup and use. Specifically, the app is installed and then you can create a share – and then generate a key – initiating a share. If you are connecting to an existing share, you create a share and provide the key for that share, and it will automagically be synced from the other clients on that share.

The most significant upside (other than P2P architecture) is that there are no storage or transfer limits – the only limitation being your local capacity.

The only significant downside to BitTorrent Sync is that synchronizations must be synchronous – since there is no cloud storage server, it requires that at least two members be online to synchronize.

For the truly insecure, TrueCrypt can be used on top of BitTorrent Sync.

Bottom Line

These are a few examples of how to secure / privatize file sharing on the Internet using relatively non-private services coupled with a few open source applications. However, it is very important to understand key management – since this security / privacy is only as secure as the keys you use to contain it. The applications themselves are fairly mature, well reviewed and generally accepted as secure.

Internet Security

How to Secure Dropbox (and others) – Part 1

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Personal security and privacy on the Internet are often seen as lost dreams – something we sacrificed in back in the 90s without a clue. In this blog, I cannot give this back to you, but my hope is to help you take back at least some parts of your personal online security / privacy piece by piece.

Background

One of the most interesting transformations in how people use the Internet is personal data convergence. In this model, a user may have a phone, a laptop, a tablet and a desktop system. Or another particular type of user would “roost” at different computers that were convenient. Personal data convergence is where that user has some mechanism or function to access and update a personal datastore from each one of these devices – fairly transparently. This is a big deal because (when done correctly) this process renders the platform or device transparent – enabling people to more effectively do what they do.

For example – at one time everybody had a home telephone, and each one had the same basic capabilities, and the primary value of having a telephone had very little to do with the actual telephone, and everything about the function and service – how it enabled the user. This personal data convergence means that each user can have their cloud of resources follow anywhere they go, and this has resulted in a proliferation of services that offer something like this. Examples include:

  • Dropbox – a basic client / server / cloud service that provides some gigabytes of data that can be synchronized between Windows, iOS, Android, Linux, OSX and others. Premium service offers more space. Free format allows any file type. Storage is at 2GB to 5GB, depending on their promotions.
  • Box – Similar to Dropbox with fewer client types supported, but more space (with the free service), which is at 10GB at this time.
  • GDrive – The Google spin on a user-centric filestore. This was originally an extension of their online office suite, and only supports specific file types.
  • Chrome – This is not a general filestore, but a specialized synchronization where all of the personal features of Chrome are stored in the Google Cloud. This includes favorites, cached usernames / passwords, cookies, history and configuration.
  • iCloud – The Apple spin of online backup / synchronization. It synchronizes and backs up the entire Apple universe of devices, but like most things Apple, there is more left unsaid than should be. We can guess that it is better than average, but no better than it has to be. But it will work well with Apple devices and it will look good the whole time.

The Issue

Each one of these has their value add / differentiator to appeal to some specific use case, but each one of these also has a significant structural security issue. In each of these services, data is essentially unsecured within the service provider. Seriously – although several (if not all) of these service providers will make strong statements about the level of encryption they use on their SSL/TLS connections and how data is encrypted on servers with some form of disk encryption, however if the keys are held by the same service provider – it means nearly nothing. In any case, this class of service is not going away – and will only increase in size and capability – but from a basic privacy and security perspective, it is one (big) step up from public storage on the Internet.

For example, right now, today – passwords for nearly every WiFi router (that is paired with a Android device – worldwide) is stored in Google servers. As part of the account backup process, Google has been backing up WiFi settings for the last several Android versions – which means hundreds of millions of WiFi passwords worldwide. Recall that Google Streetview got into some trouble over harvesting WiFi passwords, but now they build it into the Android ecosystem – and they get the passwords with no muss or fuss.

From a personal viewpoint – I see this consolidation of my online footprint, particularly private elements like usernames, passwords, and network access as something to be very uncomfortable with.

Security Theater in the Cloud

The following articles provide an entertaining juxtaposition between real security and security theater. Both are technically correct, but have very different messages.

With that perspective, now take a look at this post from Google regarding G-Drive encryption.

Yeah. As a security guy, i have to ask the question – Google and Apple have smart guys working there, lots of them. So if this is supposed to be real security, clue me in who the threat is? Based on the fact that in both cases they control the encryption and they control the keys, so it is not protected from these vendors, insider threats, anybody who could compromise their keystores, or National Security Letters. My cynical nature whispers to me and says it is security theater.

Is there a “fix” ?

For these service providers, there is no “fix” since the unsecured nature of their services is a key part of their business model. With this level of access to your personal data and files, they can build an incredibly detailed demographic profile of you as a consumer, you as a citizen, you as a security threat, and you as a future employee for any firm willing to get / buy the data. I don’t think it comes as any surprise that even if you pay for a service, a very subtle and implicit part of the cost is giving up any claim to privacy and security for the data stored in the service. This is very much a case of broken by design (and intent).  So any talk of a privacy / security “fix” is purely subjective and and not likely to be supported by the service providers. Depending on the service provider, they may consider it a violation of their terms of service. Caveat Emptor.

We have Options

If retaining your privacy and securing your personal data matter, we basically have three options.

1) Air Gap : Don’t put private / personal data in these services. It may sound excessive – but air-gapping your personal data from the Internet is the most robust privacy control you can use.

2) File Level Encryption: Use encrypted containers on the cloud sync service. Examples include Trucrypt and Keepass.

3) Private Cloud synchronization: Drop these services for something where you – the user, controls the encryption keys. Examples include BitTorrent Sync and SharePlan.

In any case, this is only part 1, and in part 2 I will expand on the options to better secure these synchronization services.