Hmm... I need to find out myself. I don't know what is the answer. I'll do some Googling and get back to you if I bump into an anything. You should email the people at Discover Card as they probably could help you..

Zone alarm is an OK fire wall. There are better ones out there but I have heard that Zone alarm requires basically no computer knowledge to set up. Any fire wall is better than none...

Sometimes that's true but not always. It's well accepted that poor security measures, including firewalls, often leads to a false sense of security. In the end, it could result in more problems than someone who was "less" protected but more vigilant...

Its more expensive, but I always recommend to friends and family to get a hardware based firewall/router. I personally like linksys Cable/DSL routers and the basic ones with a 4 port swtich built in are pretty cheap now. Last I checked, around $50.00..

Plus you get the added benefit of having more than one computer accessing your broadband internet service. I have 7 in my house including laptops (using 802.11G)..

I also have a system that I built/wrote that uses a touch screen lcd monitor at 2 locations to control lights throughout the house, display realtime video of security cameras and play user defined MP3 lists at certain locations. This has internet access as well so that I can control these things when I am away. (Plan to add voice recognition/control soon too)..

(I'm such a geek 8) ).

Linksys routers are easy to setup and easy to configure so that opening up certain ports is easy too..

Leebo..

Well OK. There is more to PC security than just one type of program..

I run /apply or do:.

1. Cookie manager program..

2. Fire wall program..

3. virus program..

4. Security patches and IE updates..

5. disk wipe program..

6. spy ware remover program..

The reviews for Zone alarm look pretty good to me..

ZoneAlarm 3.7.202.

Http://download.com.com/3000-2092-10217783...tml?tag=lst-0-4..

Linksys routers are great. But it's money..

The programs I mentioned above can all be had for free if you look around. I did actually spend $12 on a cookie program...

I am also a Linksys fan.

I can't imagine using any other networking product. I'm very brand-loyal to them. Easy to set up, easy to keep configured, great support, timely firmware updates..

I have my internet system going through two routers - one wired and one wireless. Don't ask why, I can't come up with a compelling reason yet with only one cuppa joe this morning..

I also have Zone Alarm Pro (and agree that it's very user-friendly and easy to set up, and unlike McAffee's firewall, comes pre-configured to block traffic.).

For spyware, I have PestPatrol, which seems to work well, and on my other computer I have Internet Cleanup, which works very well. Unfortunately, something in my Dell keeps it from running on this machine...

Did you use linksys for your wireless? I had problems with the one that I purchased and although I'm sure it was just that one and would have worked had I just returned it for another, I ended up just using a Belkin 802.11G 54 MBPS wireless access point..

Leebo..

The Cleaner from Moosoft seems to be a pretty good program for trojans. I've actually been happy with McAffie for my virus scanning and the personal firewall on this system..

I'm also behind a network firewall which takes care of some things like packet filtering that Linksys, and ilk, can not handle. As soon as I get a chance, I'm going to install a proxy server on it to block out even more junk..

Plus I do have a wireless+firewall+hub+router thingy as an extra NAT and port blocking layer. Talk about paranoid!..

Well I have been using the Flux Capacitor for over 5 years but unfortunately it can only be powered by Uranium which is tough to come by. It really works and it was designed by Dr Brown...

Hay Disputer, you said a bad word and are now in some NSA database as a potential terrorist. The U word is a bad word..

You aren’t by chance planning on flying any time soon?..

Well the Flux Capacitor is actually powered by plutonium (oops another bad word) but any source of 1.21 gigawatts of electricity will do. Hmm, perhaps this was the cause of THE blackout..

Stop it you going to slow the board down!.

We have 12 guests poking around the board now...

Hmm, now that I've been added to the NSA database right there next to Disputer perhaps I should get a diskwipe program too..

Erik, does the one you use also do file shredding? Of course, the ultimate diskwiper is a 1.21 gigawatt electromagnet. Downside is it might suck the iron out of your blood...

Don't forget to stop by.

Http://www.doxdesk.com/parasite/.

To see if there are any parsites attached to your browser (namely Internet Explorer ActiveX applets).

"What are parasites?.

‘Parasite’ is a shorthand term for “unsolicited commercial software” — that is, a program that gets installed on your computer which you never asked for, and which does something you probably don’t want it to, for someone else’s profit. "..

Hmmm, I'm big security nut. I'm running a Linksys router with McAfee Firewall and Antivirus. The McAfee software seems okay so far. Caught some virus that Norton Missed. The thing is you have to stay up to date with the security patches and also, keep the antivirus up to date..

It would be nice if MS would create secure software. 8)..

That's a good question..

Basically it erases the empty space on the hard drive. And yes a wipe program is the same thing as a shredding program..

Actually erasing sensitive data on a PC is a bit complex..

Normally when you delete a file on a PC you don't actually delete the file..

The analogy between a library and a hard disk is as follows..

A library, in the old days, had a card file up front that told you where a book was and then there were the shelves (stacks) of books..

A hard disk has a Master File table (MTF) and the area where all the data is stored. When you delete a file all that happens is the Operating System replaces the first letter of the file name in the MTF with a special character. This lets the Operating System that the area on the hard drive that the deleted file occupies can now be used for another file..

In actuality, without using a wiper program, there is no way to be sure that a given file that you deleted is actually gone..

Because of this fact and the fact that PC users these days put loads of sensitive data on a hard drive, it is recommended by some that before you throw out you old PC that you remove the hard drive from the PC, go to a auto parts store and purchase a T15 driver, open up the hard drive and scrape up the platters to permanently and irrevocably destroy the data. Then toss the pieces of the hard drive in the trash..

I use a little free program called Eraser 5.33:.

Http://www.tolvanen.com/eraser.

This program is very light on resources and can, given enough time, erase deleted data so completely that the FBI could not get the data back even using an electron force microscope. Of course you have to find and delete the data you want to delete yourself. This program just makes sure that what you have deleted is gone..

Date security FAQ:.

Http://www.tolvanen....raser/faq.shtml.

Here are some more technical details from the program's help file:.

"This method is based on Peter Gutmann’s paper "Secure Deletion of Data from Magnetic and Solid-State Memory". In chapter "Erasure of Data from Magnetic Media".

Erasure of Data stored on Magnetic Media.

The general concept behind an overwriting scheme is to flip each magnetic domain on the disk back and forth as much as possible (this is the basic idea behind degaussing) without writing the same pattern twice in a row. If the data was encoded directly, we could simply choose the desired overwrite pattern of ones and zeroes and write it repeatedly. However, disks generally use some form of run-length limited (RLL) encoding, so that the adjacent ones won't be written. This encoding is used to ensure that transitions aren't placed too closely together, or too far apart, which would mean the drive would lose track of where it was in the data..

To erase magnetic media, we need to overwrite it many times with alternating patterns in order to expose it to a magnetic field oscillating fast enough that it does the desired flipping of the magnetic domains in a reasonable amount of time. Unfortunately, there is a complication in that we need to saturate the disk surface to the greatest depth possible, and very high frequency signals only "scratch the surface" of the magnetic medium. Disk drive manufacturers, in trying to achieve ever-higher densities, use the highest possible frequencies, whereas we really require the lowest frequency a disk drive can produce. Even this is still rather high. The best we can do is to use the lowest frequency possible for overwrites, to penetrate as deeply as possible into the recording medium..

The write frequency also determines how effectively previous data can be overwritten due to the dependence of the field needed to cause magnetic switching on the length of time the field is applied. Tests on a number of typical disk drive heads have shown a difference of up to 20 dB in overwrite performance when data recorded at 40 kFCI (flux changes per inch), typical of recent disk drives, is overwritten with a signal varying from 0 to 100 kFCI. The best average performance for the various heads appears to be with an overwrite signal of around 10 kFCI, with the worst performance being at 100 kFCI [12]. The track write width is also affected by the write frequency - as the frequency increases, the write width decreases for both MR and TFI heads. In [13] there was a decrease in write width of around 20% as the write frequency was increased from 1 to 40 kFCI, with the decrease being most marked at the high end of the frequency range. However, the decrease in write width is balanced by a corresponding increase in the two side- erase bands so that the sum of the two remains nearly constant with frequency and equal to the DC erase width for the head.



To try to write the lowest possible frequency we must determine what decoded data to write to produce a low-frequency encoded signal..

In order to understand the theory behind the choice of data patterns to write, it is necessary to take a brief look at the recording methods used in disk drives. The main limit on recording density is that as the bit density is increased, the peaks in the analog signal recorded on the media are read at a rate which may cause them to appear to overlap, creating intersymbol interference which leads to data errors. Traditional peak detector read channels try to reduce the possibility of intersymbol interference by coding data in such a way that the analog signal peaks are separated as far as possible. The read circuitry can then accurately detect the peaks (actually the head itself only detects transitions in magnetisation, so the simplest recording code uses a transition to encode a 1 and the absence of a transition to encode a 0. The transition causes a positive/negative peak in the head output voltage (thus the name "peak detector read channel"). To recover the data, we differentiate the output and look for the zero crossings).

The separation of peaks is implemented as some form of run-length-limited, or RLL, coding..

The RLL encoding used in most current drives is described by pairs of run-length limits (d, k), where d is the minimum number of 0 symbols which must occur between each 1 symbol in the encoded data, and k is the maximum. The parameters (d, k) are chosen to place adjacent 1's far enough apart to avoid problems with intersymbol interference, but not so far apart that we lose synchronisation..

The grandfather of all RLL codes was FM, which wrote one user data bit followed by one clock bit, so that a 1 bit was encoded as two transitions (1 wavelength) while a 0 bit was encoded as one transition ( wavelength). A different approach was taken in modified FM (MFM), which suppresses the clock bit except between adjacent 0's (the ambiguity in the use of the term MFM is unfortunate. From here on it will be used to refer to modified FM rather than magnetic force microscopy). Taking three example sequences 0000, 1111, and 1010, these will be encoded as 0(1)0(1)0(1)0, 1(0)1(0)1(0)1, and 1(0)0(0)1(0)0 (where the ()s are the clock bits inserted by the encoding process). The maximum time between 1 bits is now three 0 bits (so that the peaks are no more than four encoded time periods apart), and there is always at least one 0 bit (so that the peaks in the analog signal are at least two encoded time periods apart), resulting in a (1,3) RLL code. (1,3) RLL/MFM is the oldest code still in general use today, but is only really used in floppy drives which need to remain backwards-compatible..

These constraints help avoid intersymbol interference, but the need to separate the peaks reduces the recording density and therefore the amount of data which can be stored on a disk. To increase the recording density, MFM was gradually replaced by (2,7) RLL (the original "RLL" format), and that in turn by (1,7) RLL, each of which placed less constraints on the recorded signal..

Using our knowledge of how the data is encoded, we can now choose which decoded data patterns to write in order to obtain the desired encoded signal. The three encoding methods described above cover the vast majority of magnetic disk drives. However, each of these has several possible variants. With MFM, only one is used with any frequency, but the newest (1,7) RLL code has at least half a dozen variants in use. For MFM with at most four bit times between transitions, the lowest write frequency possible is attained by writing the repeating decoded data patterns 1010 and 0101. These have a 1 bit every other "data" bit, and the intervening "clock" bits are all 0.

The best we can do here is three bit times between transitions, which is generated by repeating the decoded patterns 100100, 010010 and 001001. We should use several passes with these patterns, as MFM drives are the oldest, lowest-density drives around (this is especially true for the very-low-density floppy drives). As such, they are the easiest to recover data from with modern equipment and we need to take the most care with them..

From MFM we jump to the next simplest case, which is (1,7) RLL. Although there can be as many as 8 bit times between transitions, the lowest sustained frequency we can have in practice is 6 bit times between transitions. This is a desirable property from the point of view of the clock-recovery circuitry, and all (1,7) RLL codes seem to have this property. We now need to find a way to write the desired pattern without knowing the particular (1,7) RLL code used. We can do this by looking at the way the drives error-correction system works. The error- correction is applied to the decoded data, even though errors generally occur in the encoded data.



Decoded bits therefore depend only on nearby encoded bits, so that a repeating pattern of encoded bits will correspond to a repeating pattern of decoded bits. The repeating pattern of encoded bits is 6 bits long. Since the rate of the code is 2/3, this corresponds to a repeating pattern of 4 decoded bits. There are only 16 possibilities for this pattern, making it feasible to write all of them during the erase process. So to achieve good overwriting of (1,7) RLL disks, we write the patterns 0000, 0001, 0010, 0011, 0100, 0101, 0110, 0111, 1000, 1001, 1010, 1011, 1100, 1101, 1110, and 1111. These patterns also conveniently cover two of the ones needed for MFM overwrites, although we should add a few more iterations of the MFM-specific patterns for the reasons given above..

Finally, we have (2,7) RLL drives. These are similar to MFM in that an eight-bit-time signal can be written in some phases, but not all. A six-bit-time signal will fill in the remaining cracks. Using a encoding rate, an eight-bit-time signal corresponds to a repeating pattern of 4 data bits. The most common (2,7) RLL code is shown below:.

The most common (2,7) RLL Code.

Decoded Data (2,7) RLL Encoded Data.

00 1000.

01 0100.

100 001000.

101 100100.

111 000100.

1100 00001000.

1101 00100100.

The second most common (2,7) RLL code is the same but with the "decoded data" complemented, which doesn't alter these patterns. Writing the required encoded data can be achieved for every other phase using patterns of 0x33, 0x66, 0xCC and 0x99, which are already written for (1,7) RLL drives..

Six-bit-time patterns can be written using 3-bit repeating patterns. The all-zero and all-one patterns overlap with the (1,7) RLL patterns, leaving six others:.

001001001001001001001001.

2 4 9 2 4 9.

In binary or 0x24 0x92 0x49, 0x92 0x49 0x24 and 0x49 0x24 0x92 in hex, and.

011011011011011011011011.

6 D B 6 D B.

In binary or 0x6D 0xB6 0xDB, 0xB6 0xDB 0x6D and 0xDB 0x6D 0xB6 in hex. The first three are the same as the MFM patterns, so we need only three extra patterns to cover (2,7) RLL drives..

Although (1,7) is more popular in recent (post-1990) drives, some older hard drives do still use (2,7) RLL, and with the ever-increasing reliability of newer drives it is likely that they will remain in use for some time to come, often being passed down from one machine to another. The above three patterns also cover any problems with endianness issues, which weren't a concern in the previous two cases, but would be in this case (actually, thanks to the strong influence of IBM mainframe drives, everything seems to be uniformly big-endian within bytes, with the most significant bit being written to the disk first)..

The latest high-density drives use methods like Partial-Response Maximum-Likelihood (PRML) encoding, which may be roughly equated to the trellis encoding done by V.32 modems in that it is effective but computationally expensive. PRML codes are still RLL codes, but with somewhat different constraints. A typical code might have (0,4,4) constraints in which the 0 means that 1's in a data stream can occur right next to 0's (so that peaks in the analog readback signal are not separated), the first 4 means that there can be no more than four 0's between 1's in a data stream, and the second 4 specifies the maximum number of 0's between 1's in certain symbol subsequences. PRML codes avoid intersymbol influence errors by using digital filtering techniques to shape the read signal to exhibit desired frequency and timing characteristics (this is the "partial response" part of PRML) followed by maximum- likelihood digital data detection to determine the most likely sequence of data bits that was written to the disk (this is the "maximum likelihood" part of PRML). PRML channels achieve the same low bit error rate as standard peak-detection methods, but with much higher recording densities, while using the same heads and media. Several manufacturers are currently engaged in moving their peak-detection-based product lines across to PRML, giving a 30-40% density increase over standard RLL channels [14]..

Since PRML codes don't try to separate peaks in the same way that non-PRML RLL codes do, all we can do is to write a variety of random patterns because the processing inside the drive is too complex to second- guess. Fortunately, these drives push the limits of the magnetic media much more than older drives ever did by encoding data with much smaller magnetic domains, closer to the physical capacity of the magnetic media (the current state of the art in PRML drives has a track density of around 6700 TPI (tracks per inch) and a data recording density of 170 kFCI, nearly double that of the nearest (1,7) RLL equivalent. A convenient side-effect of these very high recording densities is that a written transition may experience the write field cycles for successive transitions, especially at the track edges where the field distribution is much broader [15]. Since this is also where remnant data is most likely to be found, this can only help in reducing the recoverability of the data). If these drives require sophisticated signal processing just to read the most recently written data, reading overwritten layers is also correspondingly more difficult. A good scrubbing with random data will do about as well as can be expected..

We now have a set of 22 overwrite patterns which should erase everything, regardless of the raw encoding. The basic disk eraser can be improved slightly by adding random passes before and after the erase process, and by performing the deterministic passes in random order to make it more difficult to guess which of the known data passes were made at which point. To deal with all this in the overwrite process, we use the sequence of 35 consecutive writes shown below:.

Overwrite Data.

PassNo. Data Written Encoding Scheme Targeted.

1 Random.

2 Random.

3 Random.

4 Random.

5 01010101 01010101 01010101 0x55 (1,7) RLL MFM.

6 10101010 10101010 10101010 0xAA (1,7) RLL MFM.

7 10010010 01001001 00100100 0x92 0x49 0x24 (2,7) RLL MFM.

8 01001001 00100100 10010010 0x49 0x24 0x92 (2,7) RLL MFM.

9 00100100 10010010 01001001 0x24 0x92 0x49 (2,7) RLL MFM.

10 00000000 00000000 00000000 0x00 (1,7) RLL (2,7) RLL.

11 00010001 00010001 00010001 0x11 (1,7) RLL.

12 00100010 00100010 00100010 0x22 (1,7) RLL.

13 00110011 00110011 00110011 0x33 (1,7) RLL (2,7) RLL.

14 01000100 01000100 01000100 0x44 (1,7) RLL.

15 01010101 01010101 01010101 0x55 (1,7) RLL MFM.

16 01100110 01100110 01100110 0x66 (1,7) RLL (2,7) RLL.

17 01110111 01110111 01110111 0x77 (1,7) RLL.

18 10001000 10001000 10001000 0x88 (1,7) RLL.

19 10011001 10011001 10011001 0x99 (1,7) RLL (2,7) RLL.

20 10101010 10101010 10101010 0xAA (1,7) RLL MFM.

21 10111011 10111011 10111011 0xBB (1,7) RLL.

22 11001100 11001100 11001100 0xCC (1,7) RLL (2,7) RLL.

23 11011101 11011101 11011101 0xDD (1,7) RLL.

24 11101110 11101110 11101110 0xEE (1,7) RLL.

25 11111111 11111111 11111111 0xFF (1,7) RLL (2,7) RLL.

26 10010010 01001001 00100100 0x92 0x49 0x24 (2,7) RLL MFM.

27 01001001 00100100 10010010 0x49 0x24 0x92 (2,7) RLL MFM.

28 00100100 10010010 01001001 0x24 0x92 0x49 (2,7) RLL MFM.

29 01101101 10110110 11011011 0x6D 0xB6 0xDB (2,7) RLL.

30 10110110 11011011 01101101 0xB6 0xDB 0x6D (2,7) RLL.

31 11011011 01101101 10110110 0xDB 0x6D 0xB6 (2,7) RLL.

32 Random.

33 Random.

34 Random.

35 Random.

The MFM-specific patterns are repeated twice because MFM drives have the lowest density and are thus particularly easy to examine. The deterministic patterns between the random writes are permuted before the write is performed, to make it more difficult for an opponent to use knowledge of the erasure data written to attempt to recover overwritten data (in fact we need to use a cryptographically strong random number generator to perform the permutations to avoid the problem of an opponent who can read the last overwrite pass being able to predict the previous passes and "echo cancel" passes by subtracting the known overwrite data)..

If the device being written to supports caching or buffering of data, this should be disabled to ensure that physical disk writes are performed for each pass instead of everything but the last pass being lost in the buffering. For example physical disk access can be forced during SCSI-2 Group 1 write commands by setting the Force Unit Access bit in the SCSI command block (although at least one popular drive has a bug which causes all writes to be ignored when this bit is set - remember to test your overwrite scheme before you deploy it). Another consideration which needs to be taken into account when trying to erase data through software is that drives conforming to some of the higher-level protocols such as the various SCSI standards are relatively free to interpret commands sent to them in whichever way they choose (as long as they still conform to the SCSI specification). Thus some drives, if sent a FORMAT UNIT command may return immediately without performing any action, may simply perform a read test on the entire disk (the most common option), or may actually write data to the disk (the SCSI- 2 standard includes an initialization pattern (IP) option for the FORMAT UNIT command, however this is not necessarily supported by existing drives)..

If the data is very sensitive and is stored on floppy disk, it can best be destroyed by removing the media from the disk liner and burning it, or by burning the entire disk, liner and all (most floppy disks burn remarkably well - albeit with quantities of oily smoke - and leave very little residue). ".

WAIT THERE IS MORE!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!.

"Methods of Recovery for Data stored on Magnetic Media.

Magnetic force microscopy (MFM) is a recent technique for imaging magnetization patterns with high resolution and minimal sample preparation. The technique is derived from scanning probe microscopy (SPM) and uses a sharp magnetic tip attached to a flexible cantilever placed close to the surface to be analysed, where it interacts with the stray field emanating from the sample. An image of the field at the surface is formed by moving the tip across the surface and measuring the force (or force gradient) as a function of position. The strength of the interaction is measured by monitoring the position of the cantilever using an optical interferometer or tunnelling sensor..

Magnetic force scanning tunneling microscopy (STM) is a more recent variant of this technique which uses a probe tip typically made by plating pure nickel onto a prepatterned surface, peeling the resulting thin film from the substrate it was plated onto and plating it with a thin layer of gold to minimise corrosion, and mounting it in a probe where it is placed at some small bias potential (typically a few tenths of a nanoamp at a few volts DC) so that electrons from the surface under test can tunnel across the gap to the probe tip (or vice versa). The probe is scanned across the surface to be analysed as a feedback system continuously adjusts the vertical position to maintain a constant current. The image is then generated in the same way as for MFM [4] [5]. Other techniques which have been used in the past to analyse magnetic media are the use of ferrofluid in combination with optical microscopes (which, with gigabit/square inch recording density is no longer feasible as the magnetic features are smaller than the wavelength of visible light) and a number of exotic techniques which require significant sample preparation and expensive equipment. In comparison, MFM can be performed through the protective overcoat applied to magnetic media, requires little or no sample preparation, and can produce results in a very short time..

Even for a relatively inexperienced user the time to start getting images of the data on a drive platter is about 5 minutes. To start getting useful images of a particular track requires more than a passing knowledge of disk formats, but these are well-documented, and once the correct location on the platter is found a single image would take approximately 2-10 minutes depending on the skill of the operator and the resolution required. With one of the more expensive MFM's it is possible to automate a collection sequence and theoretically possible to collect an image of the entire disk by changing the MFM controller software..

There are, from manufacturers sales figures, several thousand SPM's in use in the field today, some of which have special features for analysing disk drive platters, such as the vacuum chucks for standard disk drive platters along with specialised modes of operation for magnetic media analysis. These SPM's can be used with sophisticated programmable controllers and analysis software to allow automation of the data recovery process. If commercially-available SPM's are considered too expensive, it is possible to build a reasonably capable SPM for about US$1400, using a PC as a controller [6]..

Faced with techniques such as MFM, truly deleting data from magnetic media is very difficult. The problem lies in the fact that when data is written to the medium, the write head sets the polarity of most, but not all, of the magnetic domains. This is partially due to the inability of the writing device to write in exactly the same location each time, and partially due to the variations in media sensitivity and field strength over time and among devices..

In conventional terms, when a one is written to disk the media records a one, and when a zero is written the media records a zero. However the actual effect is closer to obtaining a 0.95 when a zero is overwritten with a one, and a 1.05 when a one is overwritten with a one. Normal disk circuitry is set up so that both these values are read as ones, but using specialised circuitry it is possible to work out what previous "layers" contained. The recovery of at least one or two layers of overwritten data isn't too hard to perform by reading the signal from the analog head electronics with a high-quality digital sampling oscilloscope, downloading the sampled waveform to a PC, and analysing it in software to recover the previously recorded signal. What the software does is generate an "ideal" read signal and subtract it from what was actually read, leaving as the difference the remnant of the previous signal. Since the analog circuitry in a commercial hard drive is nowhere near the quality of the circuitry in the oscilloscope used to sample the signal, the ability exists to recover a lot of extra information which isn't exploited by the hard drive electronics (although with newer channel coding techniques such as PRML (explained further on) which require extensive amounts of signal processing, the use of simple tools such as an oscilloscope to directly recover the data is no longer possible)..

Using MFM, we can go even further than this. During normal readback, a conventional head averages the signal over the track, and any remnant magnetization at the track edges simply contributes a small percentage of noise to the total signal. The sampling region is too broad to distinctly detect the remnant magnetization at the track edges, so that the overwritten data which is still present beside the new data cannot be recovered without the use of specialised techniques such as MFM or STM (in fact one of the "official" uses of MFM or STM is to evaluate the effectiveness of disk drive servo-positioning mechanisms) [7.

]. Most drives are capable of microstepping the heads for internal diagnostic and error recovery purposes (typical error recovery strategies consist of rereading tracks with slightly changed data threshold and window offsets and varying the head positioning by a few percent to either side of the track), but writing to the media while the head is off-track in order to erase the remnant signal carries too much risk of making neighbouring tracks unreadable to be useful (for this reason the microstepping capability is made very difficult to access by external means)..

These specialised techniques also allow data to be recovered from magnetic media long after the read/write head of the drive is incapable of reading anything useful. For example one experiment in AC erasure involved driving the write head with a 40 MHz square wave with an initial current of 12 mA which was dropped in 2 mA steps to a final level of 2 mA in successive passes, an order of magnitude more than the usual write current which ranges from high microamps to low milliamps. Any remnant bit patterns left by this erasing process were far too faint to be detected by the read head, but could still be observed using MFM [8]..

Even with a DC erasure process, traces of the previously recorded signal may persist until the applied DC field is several times the media coercivity [9]..

Deviations in the position of the drive head from the original track may leave significant portions of the previous data along the track edge relatively untouched. Newly written data, present as wide alternating light and dark bands in MFM and STM images, are often superimposed over previously recorded data which persists at the track edges. Regions where the old and new data coincide create continuous magnetization between the two. However, if the new transition is out of phase with the previous one, a few microns of erase band with no definite magnetization are created at the juncture of the old and new tracks. The write field in the erase band is above the coercivity of the media and would change the magnetization in these areas, but it's magnitude is not high enough to create new well- defined transitions. One experiment involved writing a fixed pattern of all 1's with a bit interval of 2.5 m, moving the write head off-track by approximately half a track width, and then writing the pattern again with a frequency slightly higher than that of the previously recorded track for a bit interval of 2.45 m to create all possible phase differences between the transitions in the old and new tracks.

Writing data at a higher frequency with the original tracks bit interval at 0.5 m and the new tracks bit interval at 0.49 m allows a single MFM image to contain all possible phase differences, showing a dramatic increase in the width of the erase band as the two tracks move from in-phase to 180 out of phase [10]..

In addition, the new track width can exhibit modulation which depends on the phase relationship between the old and new patterns, allowing the previous data to be recovered even if the old data patterns themselves are no longer distinct. The overwrite performance also depends on the position of the write head relative to the originally written track. If the head is directly aligned with the track, overwrite performance is relatively good; as the head moves offtrack, the performance drops markedly as the remnant components of the original data are read back along with the newly-written signal. This effect is less noticeable as the write frequency increases due to the greater attenuation of the field with distance [11]..

When all the above factors are combined it turns out that each track contains an image of everything ever written to it, but that the contribution from each "layer" gets progressively smaller the further back it was made. Intelligence organisations have a lot of expertise in recovering these palimpsestuous images.".

AND FINALLY!!.

"Conclusion.

Data overwritten once or twice may be recovered by subtracting what is expected to be read from a storage location from what is actually read. Data which is overwritten an arbitrarily large number of times can still be recovered provided that the new data isn't written to the same location as the original data (for magnetic media), or that the recovery attempt is carried out fairly soon after the new data was written (for RAM). For this reason it is effectively impossible to sanitise storage locations by simple overwriting them, no matter how many overwrite passes are made or what data patterns are written. However by using the relatively simple methods presented in this paper the task of an attacker can be made significantly more difficult, if not prohibitively expensive. ".

Well you asked!.

THE END!..

WHAT!? And lose their kickbacks from the AV companies?..

Why would they want to create secure software? Then their customer service people would loose their jobs. :cry:..

I wanted to add some tips on using Eraser.:.

Understanding exactly what it does is complicated. Getting it up and running is simple..

Http://www.tolvanen..../download.shtml.

After you get it installed you can, once the program is open, Click file, new task. Click on the arrow down thing and scroll down and select "local hard drives"..

Click on the schedule tab and set it for 02:00 AM or whenever you are asleep..

Click on edit, preferences, erasing, unused disk space..

Set it on option 2 (7 passes), check all three of the little boxes below and click OK..

Now minimize the pane you are in..

This will set the program to try to erase all unused disk space on your hard drive every night with 7 overwrites. If the program does not finish before you need to use the computer you will have to set the program to fewer erasing passes. 8)..

In much appreciation everyone, for your response. I now have Spybot, Alarm Zone and other various and sundries re: security. As I found out from some of you out there (mentioned in my most recent post,too ) I had to enable cookies to access my credit report (EX). But I don'pt mind that. I know none of these things are 110% Gar-ont-teed but I feel a heck of a LOT better since adding this arsenal of protection I ran two different scans just to see if they both covered all. Spybot found a bunch and could not get rid of two threats but Lavasoft Adware-6 found more and cleaned the two Spybot could get not get out.

Seems okay...

I also use Spybot S&D; with Adaware and a Black Ice Defender firewall..

However, as good as these and other products are at protecting your.

Computer, they still don't stop the broadcasting of IP addresses and.

Computer specific info..

Does anyone know of any programs that can keep your surfing habits.

Private? I'm thinking of trying Anonymizer. Has anyone tried this or.

Know anything about it?.

Thanks.

____________.

JerseyBaby..

JerseyBaby your right about that. Just look at my sig below. Here's a tip. When you get a new computer, don't put your real name in when your registering. This can also be seen by others..

Leebo, could you post some info on how to get video cameras and remote access to video(thru the web) going?.

I've been wanting to setup a video system here at the house & also be able to check on things thru the web when i'm out of town..

I already have Linksys wireless routers, but that's all so far..

Thx..

I can't get specific because the system that I designed is still a proto type so to speak, and we will be selling it on the open market next year. Most of the hardware is off the shelf, but the software is my project that controls not just "served up" video (for instance, if someone is at the door, I can use the LCD touch screen in the foyer to switch to that camera showing the area outside the door), but also controls the lights in the house (timed schedules, etc) as well as an MP3 music system. I am trying to integrate voice recognition, but haven't figured out the problem with background noise yet. Basically, you should be able to walk into the house and say "System (or any other name that signals the system to listen for a command) music on...leebo playlist...", etc. Still working on that part....

However, I can tell you that there are many systems out there for you to choose from for strictly served up video. How much money you are willing to spend will determine the quality of the video (Frames Per Second, Stationary vs. Panning cameras, etc)..

Basically, the way that most commercial systems work is that a webserver is running which will transmit video images through a web browser. Some cameras have built in webservers as well..

Here is an example of one:.

Http://iwatchlive.com/.

Here is another from a company that my company partners with to provide video surveillance (linux based):.

Http://www.tranzview.com.

Leebo..

Yes, both my routers are linksys. I had the wireless set up and running within 15 minutes. Would have been 5, but it took me 10 minutes to remember to re-set ZoneAlarm to not block the IP from the new wireless router. I've had no problems with it so far. The only problems I have with the computer that's on the wireless is the Windows Zero Configuration crap-service has to be stopped after it's connected or WZC disconnects it to look for more WAP's. Very annoying to have it happen every 3 minutes or so...

[quote="Erik"][quote]Well I have been using the Flux Capacitor for over 5 years but unfortunately it can only be powered by Uranium which is tough to come by. It really works and it was designed by Dr Brown.[/quote].

If my calculations are correct, when this baby hits 88 mph, you are gonna see some serious sh*t..

If you wish to remain anonymous on the internet, purchase Norton's Internet Security package. It cloaks your computer and people are not able to find you online (prevents hackers, etc) - but it also keeps websites from retrieving your IP address, computer name, etc. If you think you are exposing too much information, go to symantec.com and run their security check program via their website they will make tell you what information is available and what you can do to prevent it from being seen...

According to ShieldsUp!.

Your system has achieved a perfect "TruStealth" rating. Not a single packet €” solicited or otherwise €” was received from your system as a result of our security probing tests. Your system ignored and refused to reply to repeated Pings (ICMP Echo Requests). From the standpoint of the passing probes of any hacker, this machine does not exist on the Internet. Some questionable personal security systems expose their users by attempting to "counter-probe the prober", thus revealing themselves. But your system wisely remained silent in every way.



Though still not completely protected. I am thinking of a cheapo pentium compooper, slapping linux on it, and turning it to a hardware based firewall in between the router and modem..

I use to use a program called A4Proxy to hide my IP but I do not know if that program is still around. I was on a site where they have similar programs out now. I use Outpost as a firewall and NOD32 for my antivirus. You can do a google search to find sites that shows how good your firewall is and if your computer have any leaks. P.S I use to use Zone Alarm and it was good but it was also using up to much ram...