Regarding your 1st paragraph, makes no difference.

Regarding your 2nd paragraph, yes, I do.@:-)

Regarding your 3rd paragraph, So, do you have a question.

Regarding your 4th paragraph, see my 3rd paragraph.

It does because you claimed I claimed Schneir was the only expert in this space. You wrote:Which is a false and misleading statement. I made no such implication and as for elaboration (I infer then that you believe Schneir is lying) he provides a reference in his blog.

Do you disagree with the numbers Schneir posted to his blog? Is there a paper that shows that 256 bit AES is weaker than Schneir has posted? Then provide the reference.

And I think you are sarcasm challenged.

Since it was apparently unclear to you:
What difference does that make to the computational complexity to convert the ciphertext to plaintext?

What difference does that make to the computational complexity to convert the ciphertext to plaintext?

If you are simply trolling I'll add you to the ignore list to reduce mutual hassle.

You know, I think another question is being missed here.

Considering that everybody and their dog has an MP3 player nowadays, how will the CBP agents in question handle those?

A lot of people use really dumb passwords/passphrases. Social engineering for that (or interrogation) and or using dictionary attacks rather than exhaustive ones for the passphrase/password will help a lot with many people - using cryptography does not mean the same thing as using cryptography intelligently.

That said, absent some specific suspicion of criminal activity, I really wonder how much effort they'll put into cracking the encryption vs. just denying entry as a retaliation for noncompliance.

I've had a CBP agent look through my camera a couple of times (I suspect more to just validate that I was taking pictures of toursist stuff rather than looking for contraband, but who knows?), my camcorder, and my laptop. I've never been asked if I have an MP3 player (or any flash drives), but I assume if they wanted, they could quite readily hook them up to a PC to look through the contents.

I did have one ask what my old GBA media player cartridge was and when I said "That lets me play old NES games on there" replied with "Oh, it's like an emulator?"

Regarding your 1st-3rd paragraphs, here is what I stated, operative word bolded and the complete statement:

"You are implying that Schneier is somehow the only expert in cryptology and that the methods he used were the only ones that could be used(which he doesn't elaborate on). The NSA probably have some of the best cryptographers working for them. Also, if they have access to the laptop and if a hard drive encryption utility was not used, they will have access to many plaintext files as well. In addition, they have the owner's identity and personal info on him as well."

Implying and claiming are 2 different words. It's not a false and misleading statement, nor did I state Schneier was lying(though YOU interpreted it as such). You stated a single source only. Again, there are many cryptographers in the world, not just Schneier. Even if the article you posted a link to isn't Shneier's, I'll repeat, it makes no difference. Even if their shortcut attack wasn't computationally feasible, that's Schneier's experience(he uses the word we in the abstract which is stated without quotes so forgive me if I interpret it as part of his work).

Regarding your 4th paragraph, not really, my previous posts appear to have raised your dorsal fin(figuratively speaking).

Regarding your 5th-7th paragraphs, it is apparently unclear to you what my statement meant. While I was in college 4 years ago, I did a paper on EFS-Encrypting File System, a file encryption utility of Windows XP Pro and, with SP1, it uses AES 128 for encryption. While researching for the paper, I found that EFS had certain limitations which can compromise the data that is encrypted. Plaintext fragments of the encrypted data can be found in the virtual memory file, hibernation file, in temporary files on the computer, and in printer spooler files on the computer. So, if you are using any encryption utility on a PC, knowing whether plaintext fragments of the encrypted data are on the PC is very important. The computational feasibility is irrelevant if you have the plaintext of the data or a fragment of it from which to deduce other ciphertext. That's better than a shortcut or brute-force attack. Do you get it now?

Regarding your last paragraph, if you think I was trolling, you have not a clue of the term. As for adding me to your ignore list, I'll be really disappointed.:rolleyes:

Which is bad enough encryption to qualify as a straw man, and was back then; even the present Microsoft product (bitlocker) isn't much better, but at least it's full volume encryption.

All of which would be addressed by full volume encryption rather than file-by-file (as would recovering plaintext from empty space.)

All of the above can also be addressed trivially by a competent user when facing a known point in time where the machine is going to be inspected (ie customs) although they're stronger attacks when the machine can be attacked at arbitrary unknown points in time.

(Indeed, all of these points can be addressed permanently without a fully encrypted volume, once you're aware of them, at some cost of flexibility.)

In the case of Microsoft EFS or Bitlocker, you also have to trust Microsoft - a bigger issue in this case.

Regarding your 1st paragraph, per Windows Vista Resource Kit, 2nd edition, BDE's AES encryption strength can be set to 4 values: 128-bit with Diffuser(default); 256-bit with Diffuser(strongest but a performance killer, especially with an older CPU); 128-bit; 256-bit. Have you any knowledge of BDE in Windows 7. Is it any better under that OS?

Regarding your 2nd paragraph, concur but what if you are using an encryption product like TrueCrypt and set up an encrypted volume on an unencrypted hard disk. Might you not have the same problem as EFS? I have not used TrueCrypt for years and was curious.

One thing wasn't mentioned yet. Some laptops have Trusted Platform Module chips, or TPMs, which provide additional protection for the hard drive on which the encrypted data is stored.

As far as I know, the encryption strengths are the same; the changes I'm aware of in 7 have to do with better support for Bitlocker on removable media.

In any case, all of practical sense, any of these are adequate for most people's purposes - 128 bit may or may not be breakable by a serious and determined national-security adversary, but it's certainly adequate against hackers or even law enforcement for the next several years.

A better question re: Bitlocker is how they handle the key storage - if I understand correctly, the default to encrypt/decrypt the actual disk storage key using a TPM- (or USB-drive) stored RSA key, fairly similar to some of the modes of TrueCrypt. That said, it appears on a casual reading to have a good deal more complicated system for the storage and recovery of lost keys, making it much harder to trust.

Yes, in principle any access to encrypted volumes or files from a system running on an unencrypted boot volume can leave traces on that boot volume - in the worst cases a key left in plaintext somewhere in a temporary or swap file (or the registry, or a keylogger log, etc.) Good "hygiene" and avoiding a swap or hibernation file (or securely erasing and recreating those regularly) will avoid many potential attacks along those lines but short of understanding your full software platform, can't be guaranteed to avoid all of them.

Assuming your software supports it (or in some cases, such as some modes of Bitlocker, requires it), TPM has some good features which can potentially improve protection. It's been the focus of some controversy - mostly because of it's potential use for copy protection, the more worrisome applications of which have fortunately not yet appeared in the wild.

They admit it in a certain ways, as the Goverment will generally not roll out technologies they cannot break themselves. Back when they rewired the White House with fiber pretty much meant they can tap into it undetected.

Also to anyone that wants to encrypt the drive be sure to check the country you are originally going to before. Some countries have laws against high level encryption, although I think France is upto speed now.

Thank you very much for taking the time to respond.

Regarding your 3rd paragraph, per Windows Vista Resource Kit, 2nd Edition, on laptops with a TPM, the full-volume encryption key(FVEK) encrypts/decrypts the drive(using AES) and is stored in the volume metadata. In turn, the volume master key(VMK) encrypts/decrypts the FVEK and is stored on the TPM. When you authenticate to the OS, using Windows logon, the Windows startup process uses the TPM to verify that the hard disk is attached to the correct computer(has not been removed) and that important system files are intact(preventing access if malware/rootkit has compromised system integrity), before unlocking the VMK. Windows Vista can then start without prompting the user. You can add additional protection by using a BIOS-recognized USB key to store the VMK and storing the USB key in a separate location to avoid simultaneous theft of both USB key and laptop. For even greater protection, set up BDE to use a PIN. The user enters the PIN when the computer starts up, the PIN is hashed using SHA-256. The resulting hash data is sent to the TPM(which has the stored hash from when BDE was originally set up) and if the 2 match, the TPM unlocks the VMK. For even greater protection, use both the PIN and USB key option together.

As far as I know, that's the same with 7, and both Vista and 7 use some strong form of RSA (2048 bit?) for the VMK. For most people's purposes, a pre-boot PIN or passphrase should be considered essential to using an encryption mechanism like either Bitlocker or Truecrypt.

I havent read all 13 pages, but if he/she wanted to look at my laptop, I would say to see what? That it turns on? I wouldnt let them look at any of my info on my laptop.

They can refuse entry for it (and have, for some people.) Refusing to sing it in is pretty much gambling on how much of a pain-in-the-neck the particular customs officer feels like being.

Wow, so nothing is left private? Clients info, cases, personal photos, etc? Good thing for global entry, its pretty quick thru.

In principle, nothing is left private. In practice, I've never heard of them looking through documents in the absence of suspicion of a specific criminal activity - the usual fishing is just images/video.

Can you still get flagged for inspection with Global Entry?