Cost Of Spam And Why Use Anti-Spam Filter

E-mail is now being abused. The flow of spam on the Internet is the proof. It is annoying to download hundreds of disgusting spam emails into the inbox looking for some legitimate messages. Not only you waste your valuable time to delete junk emails by hand, you also waste your money as each spam message in your inbox takes precious kilobytes of bandwidth you paid for. In addition, spam messages can contain viruses, which can infect your computer system, and hidden tracking codes, which work as soon as you click on the message and let the spammer know that your email address is valid. With all that said, it would be great to delete the messages that you don’t want to receive beforehand and launch your email client to pull down only good emails. Anti-spam software can do this for you. It helps you fight against annoying spam.
There is a wide choice of anti-spam filters available on the Internet. The common services or features they offer are:
• Whitelist and Blacklist. The decision whether an email message is spam or good is taken based on the sender’s email address. The whitelist contains “friendly” email addresses, and the blacklist contains potential spammers, or simply people you don’t want to communicate with.
• Filtering based on the message subject or content. Some words or phrases are met in spam emails more often than others. These are usually vulgar or adult words (sometimes too offending). Thus, filtering based on a keyword is rather helpful.
• Virus scanning. There is possibility that spam email contains a virus in the attachment. Certain anti-spam programs allow you block emails with various suspicious attachments.
• Automatic spam detection. Some anti-spam filters can check inbound email and delete the emails they consider as spam automatically at a regular basis.
• Email recovering. Some spam blockers provide you with the ability to move spam emails to a quarantine folder and keep them for a fixed number of days. In addition, there is the possibility to recover an email from the trash if you need it.
So, with the great features and benefits that antispam software offers, you can now easily block the majority of spam emails.

Digital Signature

A digital signature is a data item, which accompanies a digitally encoded message, and which can be used to ascertain both the originator of the message and the fact that the message has not been modified since it left the originator. It is a form of authentication method which is used to authenticate the identity of the sender by convincing the recipient of a document that the person to whom the signature belongs actually signed it. An electronic document in other words can be described as any instrument that is created or stored on a computer. These include electronic mail (e-mail), letters, memos, contracts and images.
Digital signatures are mathematically tied to the document they are intended to authenticate. The most widely used type of digital signature relies on public/private key encryption. A public / private key encryption system involves two mathematically related keys that are like large passwords for each user. The private key, known only by the “signer”, can encrypt a message that only their public key can decrypt. Once the private/public keys are generated using a valid certificate authority, they remain associated with the person who generates the two keys.
The certificate authority is a trusted entity that issues certificates to end entities and other Certificate Authorities. Another important thing that Certificate Authority does is to issue Certificate Revocation Lists (CRLs) periodically and post certificates and CRLs to a database or repository.
The overall process is illustrated in the figure below:
Note: The text editor refused to accept the diagram. To view the diagram, click the website link in the resource box of the author and click on the recent articles.
System A performs a sign operation that uses A’s private key to generate the signature. System B performs a verify operation that uses system A’s public key and that allows system B to be sure that a received message originated from system A and that the contents were not modified since it left system A.
In some respects, a digital signature is similar to an integrity check value (check digit). However, there is one major difference. A digital signature must be able to support non-repudiation, that is, a recipient of a message must be able to use the digital signature to convince a third party as to the identity of the originator. A digital signature may need to be used as the basis for resolving a dispute between the originator and recipient of a message, such as a check (cheque), or business document.
RSA Digital Signature
This is a simplistic digital signature technique (named after its creators – Ronald Rivest, Adi Shamir and Len Adleman). It is one of the most popular public – key algorithms. It can be used for both encryption and digital signature. The originator of a message generates an encrypted version of the message, using RSA in authentication mode (that is, the encryption key is the private key of the originator). This encrypted version of the message is sent attached to a copy of the plaintext message. The recipient’s system, (which needs to know the corresponding decryption key - the public key of the originator), decrypts the encrypted version of the message content and compares it with the plaintext version. If the two are the same, the recipient can be assured that the originating system possessed the encryption key, and that the message contents were not changed en route.
The above scheme has some problems in terms of processing and communications overhead costs. Encryption and decryption have to be applied to the entire message contents and the volume of data sent is at least double the original message size. To overcome this problem, a hash function, which is a one-way function that maps values from a large domain into a comparatively small range, is used to generate from the content of the message to be signed, a fixed – length data item known as a message digest. The digest has the property that, in general, any change to the message will result in a different digest.
With this scheme, the originating system applies the hash function to obtain the digest, then RSA encrypts the digest to give the signature which is transmitted with the message, upon receiving the message, the recipient’s system re-computes the digest, and also RSA decrypts the signature. It then compares these two values. If they match, the recipient is assured that the originator knew the encryption key and that the message contents were not changed en route. There are several other techniques for providing digital signature

Speed Up Your Computer With Free Registry Repair

How do I speed up my computer? Tough question, if you are not familiar to the computer and software, but not to worry I have found a free registry repair software.
The free registry repair works like a charm. Do you know how many millions of unused files laying in the system? Some clear the browser cache and use windows XP disk clean up and still is difficult as more are created by the third party programs, installers, java cache files, adware and virus programs etc, so why not use the free registry repair. I am sure this free registry repair will not slow your computer daily database operation.
Keep in mind that, thousands are recorded daily, every single time, when you change, install or move software, or hardware. So use the free registry repair to assist you.
A lot of time spends to check the file locations, hardware driver aspects, and many of the different settings, so I use the free registry repair to improve the quality performance.
It is not a lot of fun to know what files or settings are no longer needed. It is impossible when repairing the computer and the free registry repair will come in handy.
Tune UP Utilities will clean up as well as delete all the old inactive files. The free registry repair does not removes many of the uninstall programs, but only the files and installation that get cluttered up. And so does the speed on boot up and day-to-day operations. It’s a noticeable difference before and after you run the free registry repair. The free registry repair has a support area and forum on their web site for any questions and issues that you have when using the free registry repair software.
Most computer sites and magazines have given Tune UP Utilities, one of the free registry repairs, the highest marks for both reliability and results. It shows how good the free registry repair is, since these expert web sites are pretty thorough in testing and don’t give high rankings all that often.
This free registry repair helps any computer speed up both the boot process and daily operations. This Tune UP Utility, one of the free registry repair, always make sure that there are no pesky viruses or adware first when release the latest version.
Did I mention that this great free registry repair is also free? I am not joking, it’s free for you, and if you are happy and find it useful, donate something so that the free registry repairs can continue their great work to make more free registry repair programs for you.

Myspace And Online Safety

The safety of children on Myspace and other social networks is of growing concern in today’s online society. The press continually talks to issues regarding child stalkers and perverts waiting around every corner of Myspace. But how much truth and risk is really involved with Myspace or its social network counter parts, and what can you do to reduce any risk that might be involved with your children using Myspace?
In reality there is a concern for younger children who use Myspace, if they have no been properly warned. Children can easily stumble upon people posing as other children. It’s very simple for someone to create a false Myspace profile, from a false email address and connect from an anonymous or false IP address. This means they’re essentially untraceable… even by the FBI, despite what they may claim.
Myspace has had a lot of bad publicity recently over sexual assaults that may have originated from connections on myspace’s network. But can you blame http://myspace.com for these actions of others? I lean away from thinking you can. The blame should lie more with parents then the connecting network. Myspace is only one of hundreds or thousands of networks and chat tools kids can use and sexual predators can take advantage of… Myspace is simply the largest and the best news story for media outlets to cover.
Parents should play an active role in monitoring their child’s internet usage, not just Myspace usage. There are monitoring tools to help keep an eye on what your kids are doing even while you’re away. Some of these programs will keep logs of every website your child visits and every chat session he or she has with friends. If your child is old enough to tell though you may want to warn him before hand as it can be a very sensitive subject for a parent to be monitoring a teenager who feels they can take care of themselves. Also these programs claim to be undetectable but keep in mind many teenagers today know more about computers than you could imagine and may be able to remove this software.
Keep an eye out on your kids and keep them safe!

Wi-fi Wireless Internet Made Simple

Just what is all this Wi-Fi wireless internet stuff they are trying to confuse and torment me with?
It is actually quite simple, useful and most of all convenient.
All you probably want to do is to share your internet connection throughout your home whether it be to other computers or so that you can sit in your bedroom and wirelessly surf the internet or send email. Perhaps as well you wish to share files such as songs throughout the computers in your house, apartment or condo.
Don’t let them confuse with all this alphabet soup - b , g , a , 11 megabytes , 54 , 108.
To begin with most any of the systems are beyond overkill. All will go faster than the even high speed broadband internet. Most use the same frequency as the standard cordless phones (2.4 GHz). . Be reassured the phones and the wireless internet in most cases will co- exist and work well with each other.
The most common wireless setups wireless b and g use the frequency most cordless phone use. G wireless internet is sort of a faster b standard. What is important to know is that it is all standardized. B will work with G and G products will work with B. G is said to up to 5 times faster than B that is assuming that you are relatively close. G wireless is very useful primarily if you are sharing large files between computers. For ordinary browsing b wireless is still overkill speed, faster as said than most broadband internet connections. The usual stated range of these wireless products is 300 feet indoors range and 1000 feet outside. The range is basically line of sight. Heavy dense objects – primarily metal, metal doors, metal foil insulation, heavy bricks and pipes and objects such as furnaces, metal filing cabinets will block reception to some degree. As well if the manufacturer makes some ultra high speed claims remember that both the router and wireless network adapters will have to be that brand and that special computer networking hardware feature to work at those high speeds and transmission rates. Remember to that wireless internet transmission speeds fall rapidly with distance.
Wireless internet is basically a radio setup with a transmitter and receivers. The transmitter is a box that plugs into the internet to share your internet connection. This is called a “Router “. . Wireless routers are made by a number of manufactures and the most widely known are the Linksys and D-Link brands. All routers are fairly good now. Tech support may be something to consider for setup ease. Routers are often sold on sale at big box stores as a means of drawing customers who already have at least one computer into their stores. It is reasoned that if a customer wants to buy a router the odds are good that he or she has more than one computer and once in the store will make additional purchases .Perhaps they will be even so fed up with the older computer as the kids have taken use of the newer faster model that the customer will even buy a additional new computer from the store.. The routers that you will find on sale will most likely be the newer g standard routers which will work with your B or G wireless network adapters in your computers.
Secondly you will need a receiver to receive the wireless internet signal at the computer end. You will have several options depending on your setup. If your laptop is a newer model then you may have a wireless “network adapter:” already built into your laptop. If you have an older laptop you can install a PCMCIA wireless network adapter into the credit card sized slot on your laptop. If you have a desktop computer you will have several options. If you have the abilities and are allowed by your warranty to open your computer case then you can install a standard PCI wireless card. The advantage of the PCI cards is that they almost always work, are screwed in so that they cannot be dislodged to stop working. The disadvantage is that the antenna of the card is hidden behind the metal of the computer case limiting reception. Another option is USB wireless adapters. Not only can the USB wireless adapter be installed without opening the case but as well with a USB extension cord the YSB network adapter can be lifted away from the computer to a higher more open place.
Several points on setup to make your life easier. After all networking is often called “Voodoo Science “. First if you are buying both the wireless adapters as well as the router try to buy the same brand, There will be easier setup , perhaps faster speed and tech support will not be able to blame the other vendor’s product for setup issues. You can tell tech support even after the return period of the store: “I guess the products are defective and have to be replaced “. There will be no issue of blaming the other vendor’s product. Case closed. Secondly most of the routers are setup by a “web based interface “. Some will come with an install disc as wizard. With others you will enter a web address usually 192.168.x.x and a password. To enter this setup interface. The instructions and passwords should be in either your instructional manual or disc that came in the box with your router. If you have a standard cable broadband account then just follow instructions if you have a DSL type of broadband internet connection then you will need the paper the phone company gave you with your internet account name and setup password. The type of connection that you set up in the router for DSL connections is called “POPE” The connection internet connection password is most likely different than your email password. This internet connection password is of very little value to anyone else. If you do not have this information phone your DSL provider tech support.
Next install the wireless adapters. Windows XP has its own wireless utility program installed. With previous versions of windows (Windows 98, 2000 and ME) you will have to install the utility program that the manufacturer provided on the install disk.
Most of his install manuals have 2 different sets of instructions – one for Windows XP, the other for the remaining operating systems.
When you setup the router you will be given a choice of whether to turn on the security features so that other people can drive up in front of your house and freeload your internet signals. It is anyone’s choice whether they wish to use this feature or not.
Believe me there will be no shortage of wireless internet connections for those freeloaders – estimate is 60 %. You can say to yourself if someone wants to waste gas to sit in front of my home to download songs or whatever good for them . If you wish to turn on the scrambling to sign onto your internet it will be in the advanced wireless or wireless security section of your router control panel. There are a number of choices. Most common is a setup called “WEP” (Web Enabled Protection)... This is available in a standard 64 bit or more secure 128 bit WEP settings. 64 bit setup is easier. 128 bit has you enter a long string of characters twice. Lots of fun with mistakes on entering those digits correctly. The easier to use security setup routines will allow an easy to use phrase code generator. For example in the phrase code generator you enter the word
Badgerlinux. The number / character code will then be generated that you must enter both the router and wireless adapter ends of your system. WEP is considered by purists not as secure as a newer system called WPA. Not all of the older hardware supports WPA. You may look at it as – if someone in my area can break into my WEP protected wireless system then that is the least of my troubles.
Lastly the biggest problem with wireless internet networks in neighbors. That is right neighbors. It is estimated that 40 % of wireless products are returned to big box stores. There are 12 available channels available in the wireless router settings. For convenience and to aid setup most brands of routers place the default channel of their routers as channel 6 right in the middle of the 12 channels available. It does not take much a signal at all to confuse your wireless adapter. You will see signal strength of your wireless route signal but you will unable to get a solid internet connection.
Worse yet this phenomenon of no internet connection may be sporadic. In many cases you will not be able to even spot the culprit in your wireless configuration software.
Remarkably wireless internet signals can travel a fair distance and may even appear to come out of nowhere. Worse yet the interference may be on sporadic. And as said it does not take much of a signal at all to leave you with no internet connection.
The answer is simplicity itself. “Change the Channel “. There are 12 available channels in your router setup control panel. The next 2 choices for wireless channel selection are at the 2 ends of the spectrum – channels 1 and 11. However it may simply be a matter of trial and error.
Wireless internet is rather amazing, you can surf the world, download songs, send email and transfer files conveniently at high speed and at some distance away from your internet connection. In addition you do not have to call or pay electrician to string the internet network wiring in your home. And if you wish to move the computers or even move just pickup and make the move.
If in the end you are having troubles on setup do not feel afraid to call tech support. Someone in India or the Philippines will be more than happy to assist you. Remember in the end you have the ultimate threat of all , that is to take your new Wi-Fi wireless products back to your store of purchase.

Getting Professional Quality Sound On Your Wedding Video

When you first look at what you’ve filmed on your new camcorder you’ll be really pleased with the results, but that initial novelty makes you immune to all the usual faults such as wobbly shots, too much panning and zooming etc. All these visual faults can easily be corrected using better techniques and a tripod or monopod.
Modern camcorder formats such as mini DV and HDV are capable of producing excellent results, especially when you edit the original tapes on one of the latest computer based editing programs to remove all the bad shots and use ‘effects’ and ‘transitions’ tastefully to enhance the finished program.
It’s not uncommon for these finished programs to end up looking great but the sound quality lets them down. The main reason for this is that the built-in video microphone is usually too far away from the people you’re filming. Some editing programs have advanced audio functions to remove unwanted artifacts and enhance the audio, however there is a limit to what these tools can achieve and it’s always better to address problems at source and not rely on some ‘magic bullet’ in Post Production.
At the time of filming, our ears, eyes and brain work together to effectively suppress the reverberation and other unwanted sound sources in the room to allow us to hear what someone is saying, what we hear is different to what a microphone ‘hears’.
Although poor sound when accompanied by pictures of the person who’s talking helps us to work out what is being said, this isn’t any use if cutaway shots are used during the dialogue, also you shouldn’t make your audience have to work hard to hear the words. This is where external microphones are needed, the closer a microphone can get to the subject, the quieter other unwanted sounds effectively become.
If, at this stage you don’t have any external microphones, then the best advice for getting good quality sound from the built in microphone is to get your camera as close to your sound source as possible i.e. for most group shots the camera should be about 6 feet away and use the wide angle lens, rather than being a long way from the group and zooming in to get the same shot size.
If you are taking videography seriously then it’s best to wear closed-back headphones so that you only hear what will be on the audio tracks.
Usually camcorders have a built in stereo electret type microphone which can be unplugged from its socket or there are external microphone sockets and some means of switching between them and the built in microphones, also an A/V socket is usually available for plugging in an external audio mixer. It might be necessary to buy a ‘stereo plug to two mono sockets’ lead so that you can make full use of the two tracks that are available on most camcorders.
So what do you want to video or what have the family press ganged you into filming? Here’s one typical event and advice on getting the best sound.
Weddings, Christenings etc
Wandering around with a camcorder during the service is distracting, so prior to the event, arrange to leave the camera on a tripod at the side of the church framed on the couple and the priest. Getting the vows is the most important shot in a wedding video, if you want other shots you’ll have to get hold of another camcorder. It’s a good idea to keep recording on that camera as well so that you only have to synchronize both shots once in the edit but just use the good sound from the main camera.
If you have a radio microphone arrange for the priest to wear it, since he’ll be the one doing most of the talking and the responses of the couple will be picked up on his microphone as he’s close to and facing them, the couple’s sound wont be as good as the priest’s but so long as they are no more than 3 feet away from the microphone it will be usable; in the edit add a bit of bass to the sections where the couple are talking and this will help to match the sound of the priest. Put fresh batteries in the transmitter and receiver, there’s no ‘take two’ in this situation.
If you don’t have a radio microphone, plug in a cardioid condenser or electret microphone into one channel of your camcorder positioned on a short stand (about 2-3 feet high) on the floor, close to where the couple will make their vows, pointing up at the couple and priest’s heads and frame the shot to just avoid the microphone. Another cardioid microphone plugged into the other channel can be put on the pulpit if the priest delivers some of the service from there.
It’s best to set audio levels before the service to ‘Auto’ or set levels manually and leave about 6dB of headroom to avoid distortion, i.e. your meter levels should just peak before the red section. Tape down cables with 2” wide tape so that no-one trips up and causes damage to themselves and the attached camera. Don’t forget to set the camera to ‘Record’ before the bride arrives and make sure you have a tape of sufficient length for the whole service.
At the reception you will have to find out who will be making speeches and arrange to put your microphones on short stands on the table or taller stands on the floor. Two microphones should give good general coverage for the ‘top table’ where the principal speakers will be; maybe arrange to get someone to position the nearest microphone infront of each speaker. The camera position wont be as limited as in the church but be extra careful with cables.
Camcorder technical issues.
For best quality sound and pictures make sure you record in ‘Standard’ mode, not ‘Long Play’ It is best to manually control volume levels (sometimes quite fiddly on domestic camcorders) or accept the potential downside of ‘pumping’ audio if you elect to use the ‘auto’ functions. Condenser microphones will need a separate power supply on most camcorders unless they are the semi-professional and professional versions, in which case you’ll have to select phantom power to be active on each channel.
For detailed advice on recording different scenarios go to http://www.recording-microphone.com/video-microphones.htm

15 Steps to Speed Up Your Computer

Your question, how do I speed up my computer? You get frustrated when your computer is very slow. You can now save yourself from aggravation especially when you are very busy working. I will show you 15 steps to do to speed up your computer. Let me enumerate them: As I have also mentioned on my previous articles 1. Defrag your computer at least once every two weeks (I do it once a week). Go to start>accessories>system tools>disk defragmenter. You can click on "analyze" first before you choose defrag, it will tell you if you need to defrag. Just defrag it even if it reports you don't need to. 2. Do Disk Clean Up at least once every two weeks (again, I do this once a week). Go to start>accessories>system tools>disk clean up. It will analyze your disk and will generate reports. I suggest you delete files from the recycle bin and the files located in the temporary files folder. Note: I avoid compressing files. It's your call. 3. Clean up your program files, delete and uninstall unwanted programs on your computer. Go to control panel>add remove programs. Make sure you restart your computer after uninstalling or removing the program so that complete deletion will take place. 4. Delete all files (temporary files and cookies from the computer). Here's how: open a browser. On top of the browser click on tools>internet options>delete files and then delete cookies. Make your history set to (0). Others wants it on at least 10. I always set mine to (0). 5. You have to be very careful in installing or downloading programs. Make sure you need it, if not please just avoid it. Uninstalling them is really hard. Many vendors has all the power to have their program stay in your computer! 6. Always turn on your firewall. I suggest you have only one firewall and one anti virus. You get less safer if you have two anti virus running (I know people who likes to have two anti virus programs running on their computer, I don't know why.) 7. Run anti-spyware programs. I trust spybot, search and destroy and the Adware from Lavasoft. I run SD every week, I do immunize them before I do the the entire program to run. I run adware every week too after I run spybot search and destroy. 8. Run complete scan using your antivirus software at least everyday (some do it once a week). Mine is scheduled at 3:00am everyday. 9. Avoid multi-tasking too much! Meaning to say, avoid opening too many programs all at the same time running at the task bar. 10. I also suggest you get a dual hard drive (which I know is now common in the market), one for the operating system only and the other for all the programs, database and files. This way, the computer boots on one hard drive. 11. Also check the performance of your computer when connected on the internet. Go to control panel >network and internet connections >network connections >right click the mouse on the connection available (e.g. local area connection "connected", "firewalled")>click on "STATUS". Make sure on the status tab, you will see the speed (mine is always 100 mbps). The packets sent and the packets received must not have a very high difference. If it is sending too much packets (as in ten times) than it receive (then try to do number 7!). 12. Always make sure you install the latest updates on your computer. 13. Always make sure all devices (drivers, etc) are properly functioning. Go to control panel >performance and maintenance >system >hardware >click on DEVICE MANAGER. You will see all the devices and adapters available on your computer. Make sure you don't see a yellow question mark (?) or this means there is an error on that device or adapter. If so, you need to update it or install the right drivers. Updated firmware might also be needed. 14. Browsing the internet? well, I have my google toolbar installed on my computer and is my default search engine. Their pop up blocker is really great! 15. A memory of at least 512 RAM might be a good idea installed on your computer There you go, 15 steps! Good luck!