Alright, you are entirely correct and yes the OP seems confused as to what analog and digital holes really are. I was under the impression that you believed the analog copy using the HD camera would be near as good as a stream copy since the OP said:
"The bitrates are just too high to be grabbing the uncompressed (aka analog) video and compressing it down for later viewing in some sort of realtime fashion."
So I thought your reply meant you believed camera would do this "real time compression" and that it would turn out great. Of course it would probably turn out looking better than an average cam but it would not be great quality, definitely not high enough quality to put it in a serious movie collection.
Sorry but the "analog hole" is crap when it comes to HD. The bitrates are just too high to be grabbing the uncompressed (aka analog) video and compressing it down for later viewing in some sort of realtime fashion. Are you saying HD camcorders don't exist?
Yeah, because the people who want to rip HD movies really want a CAM version of them (even "good" cams SUCK when displayed on my 110 inch screen I shoot my home theatre HD projector at). I don't care if the camera used is HD or not either way the quality will suck compared to being able to copy the actual uncompressed stream. Even if some of those cameras have an input like firewire or something I doubt any HD DVD player out there would output the uncompressed HD stream to the camera.
Like the OP said:
"Sorry but the "analog hole" is crap when it comes to HD."
Not everyone who wears a suit does it because they are told to. As one of the worlds few suit wearing Software Engineers I know this from experience. Suits are more comfortable, look better and certainly earn more respect than wondering around in a t-shirt and jeans, like all my coworkers.
True, not everyone wears a suit because they are told to, but I would guess the majority of people who wear them to work are told to. If you are not told to and you truly prefer wearing a suit because you think it is more comfortable then more power to you. Just remember that the majority of people (myself included!) find suits to not be as comfortable as say shorts and a t-shirt or polo shirt. Don't try and force me to wear something I don't feel comfortable in unless the job I am doing requires it.
I want t know where these jobs are that you don't interact with your clients face to face are. I mean I worked phone support for a while and I still had to deal with my client (aka my boss) face to face. I know I would appreciate it it the slack jawed admin that comes by to upgrade my computer now and again had some interest in his own personal appearance and realized that I was his client and should be treated as such.
I have one of those jobs right now (and I know that many other software developers do too). I work for a small (3 people), computer forensics software company specializing in optical media and while my title is "Software Developer" I do tech support on the phone and through e-mail as well as many other things (at a small company you need to wear many different hats at times). I have been here about 3 years and have only come face to face with a few customers and that was only because I went to some conferences such as the DoD Cybercrime Conference and TechnoForensics Conference. When I was at the conferences I wore business casual to look more presentable but when I am back in the office (where I am 99.9% of the year) I wear flip flops, khaki shorts, and a polo shirt or t-shirt (it is HOT in Phoenix!). I definitely have interest in my personal appearance and my clothes look nice and are in good shape so I would hope you wouldn't look down on my like you seem to say you would with the "slack jawed admin". Who cares if I don't have a suit, I get my job done and get it done well so what I wear should not matter as long as it is reasonable.
Oh yeah, my boss is NOT my "client", if you want to refer to your boss as your client ok but that is not cool in my book. In case you are wondering he has absolutely no issue with what I wear to work. In fact, when I showed up for the interview I had a suit on and the FIRST words out of his mouth when he saw my suit were "The dress code here is "please"." (as in "please wear something, it doesn't matter what.")
Your drive is not special, this is how DVD drives are supposed to work. I work as a developer on optical drive forensic and burning software so I know what is going on.
There are two main levels of protection on a DVD, the device level and the sector level. You are experiencing a problem at the device level, your drive needs to be "unlocked". Usually the easiest way to do that is to put your DVD in and fire up a player which will then unlock the device or like that gentoo article mentioned:
"Opening the DVD with a media player or 'filestat' from the libdvdread package before issuing the 'dd' "
From there you can't just dd however because even though you can copy the sectors they still have the CSS protection on them so you will need to do some more work if the VOB files are CSS protected to get them to play right.
However, do even the home customers get support for Ubuntu boxes?
As far as I could tell from going to Dell's Ubuntu website here http://www.dell.com/content/topics/segtopic.aspx/l inux_3x?c=us&cs=19&l=en&s=dhs&~ck=mn and then setting up a computer it appears at the end where you select your warranty and service that the extended warranty is available for the hardware just like it is for Windows boxes. So I would say yes, home customers do get support for Ubuntu boxes and yet business users cannot.
Purchase one of those and install Ubuntu yourself. It really isn't that hard and you can actually customize the install to what components you actually need. Or you could purchase one and install any free distro you want.
The HUGE problem with doing that is if the OS you install on the machine is not supported by Dell then it makes it much more of a pain in the ass if a problem pops up. You know the first thing they will say when you have a problem if they find out the OS that came with the machine is not installed is blame the problem on the OS. This goes along with another thing you said:
Remember, Dell (and any other PC company) is still a business designed to make money and if they cannot please everyone all of the time, oh well.
This is pretty true but I don't just say "oh well" to it, I say that it is really sad. If a company wants to say they support an OS then they should truly do it, not just do it for some subset of customers. My guess is the reason they do not want to support it for businesses is just a money issue, they can piss off personal users with shitty support for Ubuntu because it is such a small percentage of total customers but they DO NOT want to piss off business users who may have Ubuntu (since the whole business may get ticked off) and the easy way out is just not to support it for business and cut your losses.
Personally I would not buy a computer from Dell or any other manufacturer but that is mainly because I enjoy piecing my own computers together. I used to do the same for my friends/family too but I got sick of them blaming me for/wanting me to help them with problems with the computer all the time so I now direct them to resellers like Dell. Maybe I won't direct them to Dell anymore...
Yes, that's the classic definition. But nobody "made" you buy the car. You can take the bus. You can walk. You can ride a bicycle. The things you absolutely need to live -- food, rent, maybe some clothes -- aren't taxed.
Umm, have you EVER lived anywhere that did not have any public mass transit system setup? If you have then you would surely understand that a vehicle is nearly just as important as food, rent, and clothes. Without a car you would not have a way to get to work, buy groceries, and just get around. Sure, you might be able to rely on some friends for rides every once in a while but once it becomes commonplace your friends will stop answering your calls and always be "busy" when you need a ride.
Even in some big cities it would be pretty difficult to live without a vehicle. I live in the Phoenix, Arizona area and let me tell you the mass transit system here SUCKS. There are some buses and they are installing a light rail system but even once that is installed a car is nearly a necessity.
Try living in an area that has zero/little public mass transit and then get back to me about "nobody making you buy a car". Your view will quickly change.
But do you have the right to record the private citizen the cop is arresting?
No, you probably don't have the right to record just any citizen being arrested but in this case the person with the camera was involved in the traffic stop. From the article:
According to police, Kelly was riding in a pickup truck that had been stopped for alleged traffic violations.
I highly doubt his friend whose pickup he was riding in cared he was video taping the stop and the ONLY way I can see these charges being valid would be if the citizen being arrested wanted the charges pressed (and even still I think video taping in a public place should be allowed no matter what). This really pisses me off that some innocent 18 year old kid has to go through this bullshit because of cops who want to be assholes.
Okay, so Apple's might not be so overpriced on the laptop side but the last time I checked they still were costlier on the desktop side of things. No thanks.
That does sound cool but wouldn't having powerful magnets just out in the open like that cause a lot of problems? For instance if I had my keys in my pocket when I walked through the door would they rip through my shorts and stick to the frame? I mean you would have to ALWAYS remember to remove all metal from your body before you went into the room. I also would think that when the investigators did show up they would notice the magnetic door frame almost right as they walked into the room since they probably would have SOME metal on them or in a box of tools or something.
I guess you could set it up using an electro-magnetic system so the magnetic field was only active if the computer was powered off or something but I would doubt you could get anything powerful enough to wipe HD's that would be small enough to fit in a door frame.
That makes sense since it is a laptop (which I missed in your original post) which are prone to being stolen. It makes even more sense since Filevault is part of OSX (which I did not know) and it is so easily enabled. That is really cool, thanks for the explanation.
Wiping the disk (even numerous times) will not erase all the data. If you take a disk apart (in a clean room) you can use special HDD readers to read the electrical states of the areas that were not touched during the erasing. I read an article about this some years ago.
How long ago did you read this article? On older, less dense drives it was possible to detect "old data" but everything I have heard about modern HD's is that they are just too denses for this to work anymore. Even overwriting the whole disk one time with random data is good enough for it to be impossible to get the old data back using any electrical/magnetic state tools.
Timestomp modifies the fourth NTFS-specific filesystem attribute "entry modified" that you can't access through the standard Windows APIs (modified, access, created). You have to make a system call to get the filesystem to change it; that's what is unique and so powerful about it.
You mean it does something super powerful like go to the certain sector on the disk that contains the timestamp info bytes and edits it that way? I could come up with something to do that written in C/C++ in less than an hour. Real programmers don't rely on stuff like API's/system calls when they can easily implement the same thing themself and actually have control over it all!
Sure, you would need admin access but since this is something people want to use and isn't something that needs to be hidden that is not a problem.
Hello, there are other tools these investigators use, not just Encase, I know because I work in this field (as a developer not an investigator). Encase is mainly a case management tool, most investigators use other tools to analyze/image media and then import that data into Encase.
If I was an investigator and came across your XFS disk I would just hook the disk up to my imaging computer, throw in my linux live CD that has some tools on it as well as has the ability to work with XFS, boot up, mount your drive and then ZIP/RAR/whatever all of the files found on the drive to easily import into Encase and then just for good measure I would DD the whole disk too which can then be imported into Encase and searched if needed. Problem solved and while there definitely are some brain dead investigators the majority of them would be able to do the same exact thing.
I tried turning it on for my mum's 900MHz G3 iBook, however, and there was a slight decrease in speed - and on an already slow machine she just didn't think it was worth it.
Okay, I am curious. Just what exactly does your mum have on her computer that you even considered putting Filevault onto it?
The one and only tool I've ever heard of them using is Encase. If Encase can't find it, it doesn't exist in their world. It does do OS-X though.
You are incorrect. I work as a software developer for a US company that specializes in computer forensic software and I work with investigators all over the world as well as the US. Encase definitely is the most widely used tool but it is most definitely not the only one, other tools similar to it are FTK (also widely popular) and something called iLook.
Nearly all of the investigators I have talked to mainly use Encase for it's case management capabilities which it is really good at. It does have many other capabilities such as searching but if Encase doesn't find what they are looking for they can and will use other tools that are available. For instance, Encase does not handle optical media well if the discs contain more than one track and/or has its file system(s) set up in a funny way among other things. By just using Encase data could be overlooked and that is where the software I work on comes into play because it is specialized just for optical media. There are also many other specialized forensic tools available and any decent investigator would look into them.
Another thing I will mention is many people think if they use linux and/or OS-X that they are safe from many of the forensic tools and that is complete bullshit (even though it is true a lot of the forensic software is Windows only). It does not matter at all what OS you are running because standard operating procedure is to image all disk drives, seal up the drives, and then use forensic tools on the images and nearly all of the standard file systems are supported by some tool and even if you did use some obscure file system they could search the binary data (as long as it was not encrypted of course).
I just thought I would straighten your perception out because while it did used to be true years ago it is not the case anymore. Computer forensics is a HUGE field that has been having HUGE growth for quite some time.
If they really want to read it, though, they still can.
If you overwrite the area on the disk even once it is basically impossible to get the original data back on a modern HD. Sure, on older hard disks that for example held 25MB you could use some tricks to figure out what used to be written in that area but with modern drives the density is just too great. Overwriting once will kill the original data and overwriting it 50 times will DEFINITELY kill that data.
Since 0xFF = -1, I don't think that is agood idea.
0xFF = 255 if the value is unsigned which makes sense for sentencing people to jail/prison since negative value sentences make no sense. Unsigned also lets the maximum number of years be higher than signed which prosecuters like!
Maybe this is just too simplistic and i'm missing something, but why not block their caller ID? Each time they use a new one, slap it on the blacklist.
Not a bad idea, but could get complicated at a large organization. Especially when numbers accidently get put on the list that shouldn't be there.
If they withhold, setup your system to block all withheld numbers.
That is a good way to lose business. I definitely find blocked Caller ID numbers annoying, but many personal numbers have caller ID blocked as well as a lot of businesses. My company does a lot of business with certain 3 letter US government agencies and it is very common when they call that caller ID is blocked for them. If we were to block all unknown/unlisted numbers we would lose A LOT of business as well as have many pissed off customers and I think nearly any business would have the same problem.
There really is no great solution for the problem and it is very irritating.
I see eight nontrivial words to encode {"morning", "sun", "big", "hairy", "dog", "ate", "black", "cat"} which is way more than "~6 bytes"; try ~16.
I never claimed to know Chinese or how it works and that is why I said "possibly". Either way 16 bytes is still a hell of a lot less bytes than 55 and this is the compression for ONE SENTENCE.
A Chinese glyph is like a word, not a letter. It contains about two bytes.
I know it is like a word and not like a letter, that is why I said it could be kind of like "compression" and for my example that is why I guess that it may be possible to compress my sentence down to maybe 3 Chinese symbols taking up 6 bytes instead of 55 bytes. Even if the translation only got it down to 16 bytes that would still be a big improvement over the 55 bytes.
Not knowing Chinese, I can encode each English word with about 2 bytes of information as its ordinal position within an English dictionary (with a 65536 word vocabulary).
Okay, now WHY would you want to do that? You will be leaving out A LOT of words. One source of information that I trust claims there are over 170,000 words in the English language although about 47,000 are obsolete. However, even if you excluded the obsolete words you would still be looking at a table with over 120,000 entries in which case 2 byte encoding would just NOT work. Source here:
That is just WAY too many entries. Now compare this to Chinese symbols in which case there are only around 60,000 symbols which would work perfectly for 2 byte encoding:
"The Hanyu dacidian that came out recently in mainland China lists over 60,000 characters."
The resulting bytes from Chinese-level compression have much higher entropy (per byte) than raw English letters and don't compress as well because you've already resolved the alphabet to a 16-bit symbol table.
As long as your data storage or transmission uses ECC and EDC then the entropy of the data should not be too much of a factor. Also, who cares if it doesn't compress well after it is translated to Chinese symbols, the whole point of doing the translation was to compress the text in which case it probably did a much better job than any compression algorithm in existence. How well the translated file compresses does not matter because it already is compressed although I bet it could compress just a little bit more. The real test is to compare the size of the original text file compressed with a standard compression algorithm to the size of the same text files size after being translated to Chinese symbols, my guess is the Chinese translation will be much smaller.
It will compress down further to about the same number of bytes as compressed ordinary English
Do you understand how compression like ZIP and RAR work? I have written a ZIP compression library so I know what I am talking about. There is some overhead involved, the final archive does not only contain the compressed data. In the case of creating a text file containing the sentence I originally mentioned and then compressing it using the best possible compression in ZIP and RAR the "compressed" file actually ends up LARGER. Sure, this probably would not happen if the file contained a whole lot more text but I still think the Chinese translation would end up with much higher compression in the end.
I recently had this same fight with a guy at work who wanted to tokenize common patterns in URLs ("http", "javascript:", "img src" etc.) before we applied gzip encoding to some HTML. He wanted to implement JavaScript on the other end that would query the server for his goofy token table over AJAX after the browser decompressed the HTML "halfway" at
But Chinese characters would take up far more bits than roman letters,
Yes, each Chinese character may take up more room than each individual Roman character but what I think you are missing is that many strings of Roman characters could be "compressed" down into single Chinese characters (since each Chinese character can stand for a whole word or maybe even sentence). So, I could see this "compression" sort of working for files that are purely text but I don't think much "compression" would occur for binary files.
and there would be no patterns so it would be impossible to compress.
As illustrated above the "compression" does not occur after the Roman characters to Chinese characters conversion but during the translation. IE "In the morning sun the big, hairy, dog ate a black cat." would "compress" down into possibly a couple of Chinese characters so instead of the sentence taking ~55 bytes it may only take ~6 bytes.
No matter what I would have to guess that the "compression" gained translating to Chinese characters would be so small that it would not be worth it for large data sets and since it would mainly only work for text files it makes it much less valuable.
Believe it or not some educational institutions still teach it. I graduated with a CS degree from Northern Illinois University and COBOL classes were required. Here are links to two that they still have:
I wish I could recommend a book for you but the classes I took all used "books" printed by the university bookstore which were special made for the classes. They weren't that helpful anyway. Anyway, while it is unlikely, depending where you live you might be able to find someplace local that still has COBOL classes so I recommend checking around.
You are 100% correct and like the article mentioned COBOL is still not only used at many companies but also taught in some universities Computer Science programs including the one I graduated from being Northern Illinois University in DeKalb. Here are two examples:
There are A LOT of companies that still use COBOL out there (I saw many of them at every job fair I went to) and the langauge is far from dead. Thankfully I didn't have to go the route of being a COBOL programmer and found a job I love doing C/C++ development but at least I have the option and I definitely did learn a lot about the langauge as well as mainframe programming from taking the COBOL classes.
Another great class they teach at NIU is Assembler on an IBM System 390. That class was HARD but I love the experience and knowledge it gave me regarding how a computer works at the lower levels and I wouldn't trade that experience for anything. Here is more info on the assembler class:
Slashdot Mirror
Alright, you are entirely correct and yes the OP seems confused as to what analog and digital holes really are. I was under the impression that you believed the analog copy using the HD camera would be near as good as a stream copy since the OP said:
"The bitrates are just too high to be grabbing the uncompressed (aka analog) video and compressing it down for later viewing in some sort of realtime fashion."
So I thought your reply meant you believed camera would do this "real time compression" and that it would turn out great. Of course it would probably turn out looking better than an average cam but it would not be great quality, definitely not high enough quality to put it in a serious movie collection.
Yeah, because the people who want to rip HD movies really want a CAM version of them (even "good" cams SUCK when displayed on my 110 inch screen I shoot my home theatre HD projector at). I don't care if the camera used is HD or not either way the quality will suck compared to being able to copy the actual uncompressed stream. Even if some of those cameras have an input like firewire or something I doubt any HD DVD player out there would output the uncompressed HD stream to the camera.
Like the OP said:
"Sorry but the "analog hole" is crap when it comes to HD."
that's what they said about optical drives and laserdiscs.
CD's and DVD's ARE optical media.
Not everyone who wears a suit does it because they are told to. As one of the worlds few suit wearing Software Engineers I know this from experience. Suits are more comfortable, look better and certainly earn more respect than wondering around in a t-shirt and jeans, like all my coworkers.
True, not everyone wears a suit because they are told to, but I would guess the majority of people who wear them to work are told to. If you are not told to and you truly prefer wearing a suit because you think it is more comfortable then more power to you. Just remember that the majority of people (myself included!) find suits to not be as comfortable as say shorts and a t-shirt or polo shirt. Don't try and force me to wear something I don't feel comfortable in unless the job I am doing requires it.
I want t know where these jobs are that you don't interact with your clients face to face are. I mean I worked phone support for a while and I still had to deal with my client (aka my boss) face to face. I know I would appreciate it it the slack jawed admin that comes by to upgrade my computer now and again had some interest in his own personal appearance and realized that I was his client and should be treated as such.
I have one of those jobs right now (and I know that many other software developers do too). I work for a small (3 people), computer forensics software company specializing in optical media and while my title is "Software Developer" I do tech support on the phone and through e-mail as well as many other things (at a small company you need to wear many different hats at times). I have been here about 3 years and have only come face to face with a few customers and that was only because I went to some conferences such as the DoD Cybercrime Conference and TechnoForensics Conference. When I was at the conferences I wore business casual to look more presentable but when I am back in the office (where I am 99.9% of the year) I wear flip flops, khaki shorts, and a polo shirt or t-shirt (it is HOT in Phoenix!). I definitely have interest in my personal appearance and my clothes look nice and are in good shape so I would hope you wouldn't look down on my like you seem to say you would with the "slack jawed admin". Who cares if I don't have a suit, I get my job done and get it done well so what I wear should not matter as long as it is reasonable.
Oh yeah, my boss is NOT my "client", if you want to refer to your boss as your client ok but that is not cool in my book. In case you are wondering he has absolutely no issue with what I wear to work. In fact, when I showed up for the interview I had a suit on and the FIRST words out of his mouth when he saw my suit were "The dress code here is "please"." (as in "please wear something, it doesn't matter what.")
Your drive is not special, this is how DVD drives are supposed to work. I work as a developer on optical drive forensic and burning software so I know what is going on.
There are two main levels of protection on a DVD, the device level and the sector level. You are experiencing a problem at the device level, your drive needs to be "unlocked". Usually the easiest way to do that is to put your DVD in and fire up a player which will then unlock the device or like that gentoo article mentioned:
"Opening the DVD with a media player or 'filestat' from the libdvdread package before issuing the 'dd' "
From there you can't just dd however because even though you can copy the sectors they still have the CSS protection on them so you will need to do some more work if the VOB files are CSS protected to get them to play right.
However, do even the home customers get support for Ubuntu boxes?
l inux_3x?c=us&cs=19&l=en&s=dhs&~ck=mn and then setting up a computer it appears at the end where you select your warranty and service that the extended warranty is available for the hardware just like it is for Windows boxes. So I would say yes, home customers do get support for Ubuntu boxes and yet business users cannot.
As far as I could tell from going to Dell's Ubuntu website here http://www.dell.com/content/topics/segtopic.aspx/
Purchase one of those and install Ubuntu yourself. It really isn't that hard and you can actually customize the install to what components you actually need. Or you could purchase one and install any free distro you want.
The HUGE problem with doing that is if the OS you install on the machine is not supported by Dell then it makes it much more of a pain in the ass if a problem pops up. You know the first thing they will say when you have a problem if they find out the OS that came with the machine is not installed is blame the problem on the OS. This goes along with another thing you said:
Remember, Dell (and any other PC company) is still a business designed to make money and if they cannot please everyone all of the time, oh well.
This is pretty true but I don't just say "oh well" to it, I say that it is really sad. If a company wants to say they support an OS then they should truly do it, not just do it for some subset of customers. My guess is the reason they do not want to support it for businesses is just a money issue, they can piss off personal users with shitty support for Ubuntu because it is such a small percentage of total customers but they DO NOT want to piss off business users who may have Ubuntu (since the whole business may get ticked off) and the easy way out is just not to support it for business and cut your losses.
Personally I would not buy a computer from Dell or any other manufacturer but that is mainly because I enjoy piecing my own computers together. I used to do the same for my friends/family too but I got sick of them blaming me for/wanting me to help them with problems with the computer all the time so I now direct them to resellers like Dell. Maybe I won't direct them to Dell anymore...
Yes, that's the classic definition. But nobody "made" you buy the car. You can take the bus. You can walk. You can ride a bicycle. The things you absolutely need to live -- food, rent, maybe some clothes -- aren't taxed.
Umm, have you EVER lived anywhere that did not have any public mass transit system setup? If you have then you would surely understand that a vehicle is nearly just as important as food, rent, and clothes. Without a car you would not have a way to get to work, buy groceries, and just get around. Sure, you might be able to rely on some friends for rides every once in a while but once it becomes commonplace your friends will stop answering your calls and always be "busy" when you need a ride.
Even in some big cities it would be pretty difficult to live without a vehicle. I live in the Phoenix, Arizona area and let me tell you the mass transit system here SUCKS. There are some buses and they are installing a light rail system but even once that is installed a car is nearly a necessity.
Try living in an area that has zero/little public mass transit and then get back to me about "nobody making you buy a car". Your view will quickly change.
But do you have the right to record the private citizen the cop is arresting?
No, you probably don't have the right to record just any citizen being arrested but in this case the person with the camera was involved in the traffic stop. From the article:
According to police, Kelly was riding in a pickup truck that had been stopped for alleged traffic violations.
I highly doubt his friend whose pickup he was riding in cared he was video taping the stop and the ONLY way I can see these charges being valid would be if the citizen being arrested wanted the charges pressed (and even still I think video taping in a public place should be allowed no matter what). This really pisses me off that some innocent 18 year old kid has to go through this bullshit because of cops who want to be assholes.
Okay, so Apple's might not be so overpriced on the laptop side but the last time I checked they still were costlier on the desktop side of things. No thanks.
I would definitely add stripper poles!
That does sound cool but wouldn't having powerful magnets just out in the open like that cause a lot of problems? For instance if I had my keys in my pocket when I walked through the door would they rip through my shorts and stick to the frame? I mean you would have to ALWAYS remember to remove all metal from your body before you went into the room. I also would think that when the investigators did show up they would notice the magnetic door frame almost right as they walked into the room since they probably would have SOME metal on them or in a box of tools or something.
I guess you could set it up using an electro-magnetic system so the magnetic field was only active if the computer was powered off or something but I would doubt you could get anything powerful enough to wipe HD's that would be small enough to fit in a door frame.
Alright, too much thinking, back to work.
That makes sense since it is a laptop (which I missed in your original post) which are prone to being stolen. It makes even more sense since Filevault is part of OSX (which I did not know) and it is so easily enabled. That is really cool, thanks for the explanation.
Wiping the disk (even numerous times) will not erase all the data. If you take a disk apart (in a clean room) you can use special HDD readers to read the electrical states of the areas that were not touched during the erasing. I read an article about this some years ago.
How long ago did you read this article? On older, less dense drives it was possible to detect "old data" but everything I have heard about modern HD's is that they are just too denses for this to work anymore. Even overwriting the whole disk one time with random data is good enough for it to be impossible to get the old data back using any electrical/magnetic state tools.
Timestomp modifies the fourth NTFS-specific filesystem attribute "entry modified" that you can't access through the standard Windows APIs (modified, access, created). You have to make a system call to get the filesystem to change it; that's what is unique and so powerful about it.
You mean it does something super powerful like go to the certain sector on the disk that contains the timestamp info bytes and edits it that way? I could come up with something to do that written in C/C++ in less than an hour. Real programmers don't rely on stuff like API's/system calls when they can easily implement the same thing themself and actually have control over it all!
Sure, you would need admin access but since this is something people want to use and isn't something that needs to be hidden that is not a problem.
Another good reason to use XFS then.
Hello, there are other tools these investigators use, not just Encase, I know because I work in this field (as a developer not an investigator). Encase is mainly a case management tool, most investigators use other tools to analyze/image media and then import that data into Encase.
If I was an investigator and came across your XFS disk I would just hook the disk up to my imaging computer, throw in my linux live CD that has some tools on it as well as has the ability to work with XFS, boot up, mount your drive and then ZIP/RAR/whatever all of the files found on the drive to easily import into Encase and then just for good measure I would DD the whole disk too which can then be imported into Encase and searched if needed. Problem solved and while there definitely are some brain dead investigators the majority of them would be able to do the same exact thing.
I tried turning it on for my mum's 900MHz G3 iBook, however, and there was a slight decrease in speed - and on an already slow machine she just didn't think it was worth it.
Okay, I am curious. Just what exactly does your mum have on her computer that you even considered putting Filevault onto it?
The one and only tool I've ever heard of them using is Encase. If Encase can't find it, it doesn't exist in their world. It does do OS-X though.
You are incorrect. I work as a software developer for a US company that specializes in computer forensic software and I work with investigators all over the world as well as the US. Encase definitely is the most widely used tool but it is most definitely not the only one, other tools similar to it are FTK (also widely popular) and something called iLook.
Nearly all of the investigators I have talked to mainly use Encase for it's case management capabilities which it is really good at. It does have many other capabilities such as searching but if Encase doesn't find what they are looking for they can and will use other tools that are available. For instance, Encase does not handle optical media well if the discs contain more than one track and/or has its file system(s) set up in a funny way among other things. By just using Encase data could be overlooked and that is where the software I work on comes into play because it is specialized just for optical media. There are also many other specialized forensic tools available and any decent investigator would look into them.
Another thing I will mention is many people think if they use linux and/or OS-X that they are safe from many of the forensic tools and that is complete bullshit (even though it is true a lot of the forensic software is Windows only). It does not matter at all what OS you are running because standard operating procedure is to image all disk drives, seal up the drives, and then use forensic tools on the images and nearly all of the standard file systems are supported by some tool and even if you did use some obscure file system they could search the binary data (as long as it was not encrypted of course).
I just thought I would straighten your perception out because while it did used to be true years ago it is not the case anymore. Computer forensics is a HUGE field that has been having HUGE growth for quite some time.
If they really want to read it, though, they still can.
If you overwrite the area on the disk even once it is basically impossible to get the original data back on a modern HD. Sure, on older hard disks that for example held 25MB you could use some tricks to figure out what used to be written in that area but with modern drives the density is just too great. Overwriting once will kill the original data and overwriting it 50 times will DEFINITELY kill that data.
Since 0xFF = -1, I don't think that is agood idea.
0xFF = 255 if the value is unsigned which makes sense for sentencing people to jail/prison since negative value sentences make no sense. Unsigned also lets the maximum number of years be higher than signed which prosecuters like!
Maybe this is just too simplistic and i'm missing something, but why not block their caller ID? Each time they use a new one, slap it on the blacklist.
Not a bad idea, but could get complicated at a large organization. Especially when numbers accidently get put on the list that shouldn't be there.
If they withhold, setup your system to block all withheld numbers.
That is a good way to lose business. I definitely find blocked Caller ID numbers annoying, but many personal numbers have caller ID blocked as well as a lot of businesses. My company does a lot of business with certain 3 letter US government agencies and it is very common when they call that caller ID is blocked for them. If we were to block all unknown/unlisted numbers we would lose A LOT of business as well as have many pissed off customers and I think nearly any business would have the same problem.
There really is no great solution for the problem and it is very irritating.
I see eight nontrivial words to encode {"morning", "sun", "big", "hairy", "dog", "ate", "black", "cat"} which is way more than "~6 bytes"; try ~16.
I never claimed to know Chinese or how it works and that is why I said "possibly". Either way 16 bytes is still a hell of a lot less bytes than 55 and this is the compression for ONE SENTENCE.
A Chinese glyph is like a word, not a letter. It contains about two bytes.
I know it is like a word and not like a letter, that is why I said it could be kind of like "compression" and for my example that is why I guess that it may be possible to compress my sentence down to maybe 3 Chinese symbols taking up 6 bytes instead of 55 bytes. Even if the translation only got it down to 16 bytes that would still be a big improvement over the 55 bytes.
Not knowing Chinese, I can encode each English word with about 2 bytes of information as its ordinal position within an English dictionary (with a 65536 word vocabulary).
Okay, now WHY would you want to do that? You will be leaving out A LOT of words. One source of information that I trust claims there are over 170,000 words in the English language although about 47,000 are obsolete. However, even if you excluded the obsolete words you would still be looking at a table with over 120,000 entries in which case 2 byte encoding would just NOT work. Source here:
http://www.askoxford.com/asktheexperts/faq/abouten glish/numberwords
That is just WAY too many entries. Now compare this to Chinese symbols in which case there are only around 60,000 symbols which would work perfectly for 2 byte encoding:
"The Hanyu dacidian that came out recently in mainland China lists over 60,000 characters."
http://www.logoi.com/notes/chinese_symbols.html
The resulting bytes from Chinese-level compression have much higher entropy (per byte) than raw English letters and don't compress as well because you've already resolved the alphabet to a 16-bit symbol table.
As long as your data storage or transmission uses ECC and EDC then the entropy of the data should not be too much of a factor. Also, who cares if it doesn't compress well after it is translated to Chinese symbols, the whole point of doing the translation was to compress the text in which case it probably did a much better job than any compression algorithm in existence. How well the translated file compresses does not matter because it already is compressed although I bet it could compress just a little bit more. The real test is to compare the size of the original text file compressed with a standard compression algorithm to the size of the same text files size after being translated to Chinese symbols, my guess is the Chinese translation will be much smaller.
It will compress down further to about the same number of bytes as compressed ordinary English
Do you understand how compression like ZIP and RAR work? I have written a ZIP compression library so I know what I am talking about. There is some overhead involved, the final archive does not only contain the compressed data. In the case of creating a text file containing the sentence I originally mentioned and then compressing it using the best possible compression in ZIP and RAR the "compressed" file actually ends up LARGER. Sure, this probably would not happen if the file contained a whole lot more text but I still think the Chinese translation would end up with much higher compression in the end.
I recently had this same fight with a guy at work who wanted to tokenize common patterns in URLs ("http", "javascript:", "img src" etc.) before we applied gzip encoding to some HTML. He wanted to implement JavaScript on the other end that would query the server for his goofy token table over AJAX after the browser decompressed the HTML "halfway" at
But Chinese characters would take up far more bits than roman letters,
Yes, each Chinese character may take up more room than each individual Roman character but what I think you are missing is that many strings of Roman characters could be "compressed" down into single Chinese characters (since each Chinese character can stand for a whole word or maybe even sentence). So, I could see this "compression" sort of working for files that are purely text but I don't think much "compression" would occur for binary files.
and there would be no patterns so it would be impossible to compress.
As illustrated above the "compression" does not occur after the Roman characters to Chinese characters conversion but during the translation. IE "In the morning sun the big, hairy, dog ate a black cat." would "compress" down into possibly a couple of Chinese characters so instead of the sentence taking ~55 bytes it may only take ~6 bytes.
No matter what I would have to guess that the "compression" gained translating to Chinese characters would be so small that it would not be worth it for large data sets and since it would mainly only work for text files it makes it much less valuable.
How would one go about learning COBOL today?
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Believe it or not some educational institutions still teach it. I graduated with a CS degree from Northern Illinois University and COBOL classes were required. Here are links to two that they still have:
http://www.cs.niu.edu/undergrad/coursecat.html#25
http://www.cs.niu.edu/undergrad/coursecat.html#46
I wish I could recommend a book for you but the classes I took all used "books" printed by the university bookstore which were special made for the classes. They weren't that helpful anyway. Anyway, while it is unlikely, depending where you live you might be able to find someplace local that still has COBOL classes so I recommend checking around.
COBOL may be dying, but it's lingering on...
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You are 100% correct and like the article mentioned COBOL is still not only used at many companies but also taught in some universities Computer Science programs including the one I graduated from being Northern Illinois University in DeKalb. Here are two examples:
http://www.cs.niu.edu/undergrad/coursecat.html#25
http://www.cs.niu.edu/undergrad/coursecat.html#46
There are A LOT of companies that still use COBOL out there (I saw many of them at every job fair I went to) and the langauge is far from dead. Thankfully I didn't have to go the route of being a COBOL programmer and found a job I love doing C/C++ development but at least I have the option and I definitely did learn a lot about the langauge as well as mainframe programming from taking the COBOL classes.
Another great class they teach at NIU is Assembler on an IBM System 390. That class was HARD but I love the experience and knowledge it gave me regarding how a computer works at the lower levels and I wouldn't trade that experience for anything. Here is more info on the assembler class:
http://www.cs.niu.edu/undergrad/coursecat.html#36
While I am not exactly happy that COBOL is still around it still is a fact that it is going nowhere anytime soon.