If there is data on your PC that you need to protect, BitLocker encryption can help to protect your files with encryption. (As noted on the Windows 7 site, BitLocker "helps keep everything from documents to passwords safer by encrypting the entire drive that Windows and your data reside on. Once BitLocker is turned on, any file you save on that drive is encrypted automatically.")
Last week I read several articles in the news – like this one on arstechnica – about commercial tools that claim to crack BitLocker and take advantage of weaknesses. Of interest today is Paul Cooke’s post over on the Windows Team Blog on Windows BitLocker Claims and that to say these tools break BitLocker "is a bit of a misnomer"…
"Windows 7 is seeing success in the marketplace which I am very happy about from a security perspective. The Microsoft Security Intelligence Report has shown us again and again that the more up-to-date a PC is, the less likely it is to be infected by malware and other potentially dangerous software. So Windows 7 making strides is helpful to the ecosystem overall from a security standpoint. Success comes at a price though, through greater scrutiny and misinterpretation of some of the technologies. One of those technologies is BitLocker.
"Our customers are confronted with a wide spectrum of data security threats that are specific to their environment and we work hard to provide capabilities and information to help the customer achieve the right balance of security, manageability, and ease-of-use for their specific circumstances. BitLocker is an effective solution to help safeguard personal and private data on mobile PCs and provides a number of protection options that meet different end-user needs. Like most full volume encryption products on the market, BitLocker uses a key-in memory when the system is running in order to encrypt/decrypt data on the fly for the drives in use. Also like other encryption products, a determined adversary has significant advantages when they have physical access to a computer.
"We recognize users want advice with regards to BitLocker and have published best practice guidance in The Data Encryption Toolkit for Mobile PCs. In the toolkit, we discuss the balance of security and usability and detail that the most secure method to use BitLocker in hibernate mode and a TPM+PIN configuration. Using this method, a machine that is powered off or hibernated will protect users from the ability to extract a physical memory image of the computer.
"Windows 7 BitLocker continues to be a foundational component adding to any defense in depth strategy for securing systems, and specifically laptops. Even with the great enhancements made in Windows 7 such as BitLocker To Go, it still remains that BitLocker alone is not a complete security solution. IT professionals as well as users must be diligent when protecting IT resources and the best protection against these sorts of targeted attacks requires more than just technology: it requires end user education and physical security also play important roles."
As Ars pointed out in an updated post…
"… this isn’t exactly a "crack" for BitLocker. Like most similar digital forensics analysis software, Passware Kit Forensic requires access to a physical memory image file of the target computer before it can extract all the encryption keys for a BitLocker disk. If a forensics analyst or thief has physical access to a running system, it is possible to take advantage of the fact that the contents are in the computer’s memory. Other drive encryption programs have similar issues."
Learn more about BitLocker…
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