The 2018 Audi A8 is here, and like all German flagship sedans it looks like it will be wildly over-engineered. Among the endless luxury features in the new sedan, one. Media corporations have always used the term copy protection, but critics argue that the term tends to sway the public into identifying with the publishers, who favor.You Suck At Aerodynamics. Don’t feel bad. Everybody sucks at aerodynamics. Well, I guess people who have actually studied aerodynamics don’t, but as far as us normal, everyday jackasses?
We’re terrible. Or at least, I am, when it comes to looking at cars and guessing how aerodynamic they are. I realized this when my friend Tom Jennings sent me a link he found of a blog entry from a guy who bought a 1. The World of Automobiles. The bloggist, someone called Tamerlane, had scanned a couple pages from the encyclopedia showing the coefficient of drag (Cd) of a bunch of well- known cars. If you’ve ever thought you could guess the Cd of a car by looking at it, that chart should be enough to humble you. Aerodynamics are far more complex than we think, and things that look sleek often aren’t, at least according to the wind. So, to have some fun, I’ve grabbed some of the lovely, simple illustrations from the chart and turned them into a series of little visual quizzes: two cars per image, and you can try and guess which one is more aerodynamic, which, of course, means a lower Cd number. Actually, that’s not exactly true; as many commenters have pointed out, I’m a drooling simpleton who doesn’t understand how important frontal area is to aerodynamics. So, keep that in mind. Frontal area is a big deal, and I’m an idiot. You can see the answers by sliding the red bar to the left. I sure hope this works on mobile platforms! Want to give it a try? No cheating, now! We have fun here, don’t we? Copy protection - Wikipedia. Copy protection, also known as content protection, copy prevention and copy restriction, is any effort designed to prevent the reproduction of software, films, music, and other media, usually for copyrightreasons. Unauthorized copying and distribution accounted for $2. United States alone in the 1. Some methods of copy protection have also led to criticisms because it caused inconvenience for honest consumers, or it secretly installed additional or unwanted software to detect copying activities on the consumer's computer. Making copy protection effective while protecting consumer rights is still an ongoing problem with media publication. Terminology. Digital rights management is a more general term because it includes all sorts of management of works, including copy restrictions. Copy protection may include measures that are not digital. A more appropriate term may be . Some even argue that free copies increase profit; people who receive a free copy of a music CD may then go and buy more of that band's music, which they would not have done otherwise. Some publishers have avoided copy- protecting their products, on the theory that the resulting inconvenience to their users outweighs any benefit of frustrating . DRM and license managers sometimes fail, are inconvenient to use, and may not afford the user all of the legal use of the product he has purchased. The term copy protection refers to the technology used to attempt to frustrate copying, and not to the legal remedies available to publishers or authors whose copyrights are violated. Software usage models range from node locking to floating licenses (where a fixed number licenses can be concurrently used across an enterprise), grid computing (where multiple computers function as one unit and so use a common license) and electronic licensing (where features can be purchased and activated online). The term license management refers to broad platforms which enable the specification, enforcement and tracking of software licenses. To safeguard copy protection and license management technologies themselves against tampering and hacking, software anti- tamper methods are used. Floating licenses are also being referred to as Indirect Licenses, and are licenses that at the time they are issued, there is no actually user who will use them. That has some technical influence over some of their characteristics. Direct Licenses are issued after a certain user requires it. As an example, an activated Microsoft product, contains a Direct License which is locked to the PC where the product is installed. From business standpoint, on the other hand, some services now try to monetize on additional services other than the media content so users can have better experience than simply obtaining the copied product. The basic technical fact is that all types of media require a . The player has to be able to read the media in order to display it to a human. In turn, then, logically, a player could be built that first reads the media, and then writes out an exact copy of what was read, to the same type of media. At a minimum, digital copy protection of non- interactive works is subject to the analog hole: regardless of any digital restrictions, if music can be heard by the human ear, it can also be recorded (at the very least, with a microphone and tape recorder); if a film can be viewed by the human eye, it can also be recorded (at the very least, with a video camera and recorder). In practice, almost- perfect copies can typically be made by tapping into the analog output of a player (e. Copying text- based content in this way is more tedious, but the same principle applies: if it can be printed or displayed, it can also be scanned and OCRed. With basic software and some patience, these techniques can be applied by a typical computer- literate user. Since these basic technical facts exist, it follows that a determined individual will definitely succeed in copying any media, given enough time and resources. Media publishers understand this; copy protection is not intended to stop professional operations involved in the unauthorized mass duplication of media, but rather to stop . They can be encrypted in a fashion which is unique for each user's computer, and the decryption system can be made tamper- resistant. Methods. These were (and are) programmers who would defeat copy protection on software as a hobby, add their alias to the title screen, and then distribute the . Software prices were comparable with audio cassette prices. So have those who used TRS- DOS, and I understand that MS- DOS has copy protection features. The first copy protection was for cassette tapes and consisted of a loader at the beginning of the tape, which read a specially formatted section which followed. The first protection of floppy disks consisted of changing the address marks, bit slip marks, data marks, or end of data marks for each sector. For example, Apple’s standard sector markings were: D5 AA 9. That was followed by track, sector, and checksum. DE AA EB concluded the address header with what are known as bit slip marks. D5 AA AD was used for the data mark and the end of data mark was another DE AA EB. Changing any of these marks required fairly minimal changes to the software routines in Apple DOS which read and wrote the floppy disk, but produced a disk that could not be copied by any of the standard copiers, such as Apple's COPYA program. Some protection schemes used more complicated systems that changed the marks by track or even within a track. Locksmith. He did not believe that it was useful, writing in 1. Most involve so- called nibble/nybble copiers, which try to analyze the original disk and then make a copy. It's going to dry up the software. There ought to be some way to stop . These copiers reproduced copy protected floppy disks an entire track at a time, ignoring how the sectors were marked. This was harder to do than it sounds for two reasons: firstly, Apple disks did not use the index hole to mark the start of a track; their drives could not even detect the index hole. Tracks could thus start anywhere, but the copied track had to have this . Secondly, Apple used special . These bytes were written as normal data bytes followed by a slightly longer than normal pause, which was notoriously unreliable to detect on read- back; still, you had to get the self- sync bytes roughly right as without them being present in the right places, the copy would not work, and with them present in too many places, the track would not fit on the destination disk. Locksmith copied Apple II disks by taking advantage of the fact that these sync fields between sectors almost always consisted of a long string of FF (hex) bytes. It found the longest string of FFs, which usually occurred between the last and first sectors on each track, and began writing the track in the middle of that; also it assumed that any long string of FF bytes was a sync sequence and introduced the necessary short pauses after writing each of them to the copy. Ironically, Locksmith would not copy itself. The first Locksmith measured the distance between sector 1 of each track. Copy protection engineers quickly figured out what Locksmith was doing and began to use the same technique to defeat it. Locksmith countered by introducing the ability to reproduce track alignment and prevented itself from being copied by embedding a special sequence of nibbles, that if found, would stop the copy process. Henry Roberts (CTO of Nalpeiron), a graduate student in computer science at the University of South Carolina, reverse engineered Locksmith, found the sequence and distributed the information to some of the 7 or 8 people producing copy protection at the time. For some time, Locksmith continued to defeat virtually all of the copy protection systems in existence. The next advance came from Henry Roberts' thesis on software copy protection, which devised a way of replacing Apple’s sync field of FFs with random appearing patterns of bytes. Because the graduate student had frequent copy protection discussions with Apple’s copy protection engineer, Apple developed a copy protection system which made use of this technique. Henry Roberts then wrote a competitive program to Locksmith, Back It UP. He devised several methods for defeating that, and ultimately a method was devised for reading self sync fields directly, regardless of what nibbles they contained. Copy protection sometimes caused software to not run on clones, such as the Apple II- compatible Laser 1. Such a scheme had been used for the Play. Station and could not be circumvented easily without the use of a modchip. For software publishers, a less expensive method of copy protection is to write the software so that it requires some evidence from the user that they have actually purchased the software, usually by asking a question that only a user with a software manual could answer (for example, . However, this approach can be exploited with the patience to copy the manual with a photocopier, and it also suffers from the issue of making the product more inconvenient for the end user to use. Recent practices. Serial number in ROM could not be used because some machines do not have them. Some popular surrogate for a machine serial number were date and time (to the second) of initialization of the hard disk or MAC address of Ethernet cards (although this is programmable on modern cards). With the rise of virtualization, however, the practice of locking has to add to these simple hardware parameters to still prevent copying. Unauthorized users are not allowed to install or use the software. Microsoft's Windows Genuine Advantage system is a far- reaching example of this. With rise of Cloud computing, requiring Internet access is becoming more popular for software verification. Beyond online authentication, a standalone software may be integrated with the cloud so that key data or code is stored online.
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