TapSpam challenged

24 Nov 2006 12:31 by Rick

There are a number of systems around which try to verify the sender’s email address before passing the incoming mail onto you. One of the popular ones is Challenge-Response. What it does is work with a whitelist of known email addresses. If the mail comes from one of these it passes it into your inbox. Fine. If it comes from an unknown address then it doesn’t just delete it, which is good, but it sends back an automated reply to the sender asking them to verify that they really did send the email in the first place. This sounds good; what happens is the person who wrote to you has to reply in a particular way or visit a web site to verify their address and then the original email is passed into your inbox. However if the email came from a spammer then they won’t reply and you will never see the original mail.

What is wrong with this; I am getting the mail I want and not getting the spam?

There are a number of answers to this. Firstly, you are making your correspondents jump through hoops just to write to you. Of course you will have put all your known correspondents into your whitelist already but that unexpected enquiry from someone who has read your blog, or auntie Jean who has just got an AOL account or a friend who has had to change providers will have to perform unnatural acts. Auntie Jean may never figure it out. Do you mind if you never receive the receipt from that widget you bought online.

Secondly, if you are a member of any mailing list, what happens if someone new joins. Their first mail goes to the list which is passed on to you. Your system replies asking for validation—but he has never heard of you. Worse still, your challenge may go to the list for everyone to see.

Third, what if the sender is using a similar system, what happens to your response (exercise for the reader).

Finally, and most importantly, it makes YOU a spammer. All those challenge replies you send, an equal number to the spam you receive, contribute to the network load. And where do you think they are going? Not to the spammer because he was careful not to put his own address on it; the return addresses are all forged, and a good percentage of them will belong to real users who not only get their normal ration of spam but are now also getting yours as well. And don’t think your ISP won’t notice either. They are used to large volumes of incoming mail because they know about spam but suddenly you are generating large volumes of outgoing mail as well; and they know about spam so are liable to cut you off.

TapSize matters

08:30 by Rick

When planning a video projector system for a church, or anywhere else for that matter, you need to do things in the right order. The first thing to decide is what sort of material you are going to project: is it cinema type video, detailed business type presentations or are words of hymns the main objective. These determine the shape and most importantly the size of screen that you require. This must come before choosing your projector. Most online advice guides ignore the first criteria—type of presentation.

For the cinema type of experience you will probably want a 16:9 format screen and most of the advice online will be able to assist you to decide the size. The consensus seems to be a screen height 1/6th the distance to the back row of seats. You may also want at least a partial blackout.

For a business presentation you would probably want a 4:3 format and, unless you wanted very fine detail, you could probably go to a screen height 1/8th the distance to the back row.

For a system primarily for the words of hymns and scripture then it is a different prospect altogether. Doing the calculations for our church, which is 24m from front to back (we don’t have a chancel/choir area), we get a screen 7m x 4m for cinema and 4m x 3m for business. Without exaggerating — this is HUGE. Even the smaller would completely dominate the front of the worship area and the larger would block out all view of the East window and generally annoy everyone including the diocesan architects.

Fortunately we consulted a good professional contractor who knows churches and he put us right (in fact we consulted two and got similar answers). The difference is that you are rarely showing more than a dozen lines of text on the screen at once. Any more than that and the reader will lose their place. Hence you can use very large text sizes which reduces the necessary size of the screen. You can still do video clips and pictures for illustration but you are not aiming at that all enveloping cinema experience. Many years experience also tells me that only about half the members turn up to church business meetings so pack them into the front when you want to display the detailed financials.

So, taking the advice, we determined that we only needed an 8′ wide screen (that is about 2.4m) and I have been holding off posting this item until I had seen it in action: he was right! The benefits were great. It was much cheaper (both screen and projector), it is not overly obtrusive, and it folds away neatly when not in use. I can just about read it from the middle without my glasses and I my sight is pretty poor. It is perfect from right at the back with them on.

TapBooze Lose

23 Nov 2006 09:49 by Rick

The news this morning is full of commentary on the probability that the European Court will declare that Excise Duty should be paid at source even for transactions across member country’s borders. This means that if I buy wine (for personal use) on the internet from a French dealer then I will pay French tax and duty, not British. Some of the implications of this, which also applies to tobacco, are being discussed e.g. the lower price paid by the purchaser, the impact on the local retailer, the death of the traditional Booze Cruise trips to Calais and also the impact on the Exchequer. Here are a few other effects that have not been mentioned.

  • Another subject for the spammers to get their hooks into.
  • Many people already buy from mail order dealers so unless they move sharply, the loss to their trade; one I know has only just moved its distribution from one location in the UK to another. I would imagine that specialist sales companies will be established, probably subsidiaries of the existing mail order retailers. I don’t think buying direct from the vineyard will be commonplace.
  • Another market for the scammers and dodgy web sites.
  • The extra workload on Customs and Excise and police checking that it is “for personal use”—even more of a problem since their income will have dried up.
  • The removal of the tax disincentive which has been used for many years to dissuade people from smoking and to a lesser extent drinking.
  • In theory the same ruling would apply to motor fuel but I can’t think of a practical way to arrange personal imports.
  • If the ruling comes into effect immediately, consider the rush for Christmas.
  • There is the possibility of theft en route. The transport is likely to be of lower security than bulk imports by dealers and, because it is the purchaser’s responsibility, will need to be insured by them.
  • The increased transport costs and impact; for example consider the export of Scotch to a low tax EU county only to be purchased by mail order to be sent to a Glasgow customer.

TapAVG Free

22 Nov 2006 14:12 by Rick

In case you are confused by the recent pop-up messages, and the news reports suggest you may be, Grisoft still have a free version of AVG Anti-Virus available and it is even better than it used to be. All that is happening is that v7.1 is going out of currency and you need to upgrade to 7.5. It is not as easy to find as it used to be but is still the best value product out there. I haven’t tried the Anti-Spyware tool yet.

AVG Free Advisor: Free Anti-virus, anti-spyware and anti-malware tools

TapPassports cracked

17 Nov 2006 09:00 by Rick

The principle task for an interviewee on the Today program is to get John Humphrys to understand what you are talking about. I congratulate the spokesman from NO2ID for achieving that delicate task, this morning when he clearly explained the problems with the new RFID passports with no hype or ranting.

Thanks, too, to Michael for sending me a link to a very funny, but disturbing piece of fiction. Unfortunately I can’t find it now; Perhaps if I ask nicely he will post it in a comment here.

TapPretty vacant

08:54 by Rick

If David Cameron had made a speech in which he referred to Patricia Hewitt as “Quite pretty but a lightweight” there would have been an uproar and shouts of “sexist”. The speaker would probably have had to suspend the sitting whilst order was restored; the fallout may have affected his chances in the next election. But it seems that when the situation is reversed then it is quite acceptable; there was barely a murmur when she patronised him in that manner. Perhaps this is an indication that non-PC language is now acceptable, and I say three cheers to that.

TapLicence to Sing

15 Nov 2006 10:04 by Rick

When we started the investigation to change over from using hymn books to projecting words of songs onto a screen, the administrative position looked straight forward. We had a CCL licence and we would note which songs were used for the annual report. We were already doing it for intermittent photocopies and the projection software may even help by recording the activity for us.

Whilst loading whatever songs I could lay my hands on in electronic format I spotted a hitch. Songs of Fellowship helpfully provides a disc containing all the words, originally formatted for OHP slides but easy to translate into most projection software using utility programs. Whilst doing this I spotted a rider on one of the songs which said that “songs published by the Taizé Community were not covered by the CCL licence and permission to copy or display had to be sought directly” (or words similar to that). I did some research and found that there were lots of others in the same position. The well known books such as Mission Praise and the big publishing houses like Kingsway and Integrity Music are well covered by the CCL licence but some others, particularly those in the catholic tradition, are not.

Many years ago we put together a song book of our own as we couldn’t find a published book which covered the wide range of material that we needed and didn’t want to give out an arm full of books every service. It is many songs from this book that we now have difficulty with. At the time each song was researched and permission sought from the copyright holder, sometimes with a royalty fee. It looks like that, now we wish to change media, we have to start this all over again.

The availability of the CCL licence has certainly made multi-media worship easier, but it has not eliminated all of the problems.

TapPackaging

13 Nov 2006 09:06 by Rick

Sorry for the lack of posts recently, I have been veeery busy with the church video system. We are nearly there now.

Anyway, there was an item of note on the news this morning about supermarkets doing more to reduce packaging and marking those items which can be recycled. For once I have some sympathy with the mega-chains. How can they sensibly label packages for recycling when the local authorities who organise the recycling are all at odds with each other. Here they don’t recycle plastic at all unless you take it to one of the two depots or a few isolated collection points. The council just to the north, in the area where I work, the system is totally different. If you stand on the border you can see both systems in operation with different categories, timing and collection policies.
Returning the sympathetic view, the collectors and consumers do also have a problem distinguishing the different sorts of plastic so perhaps if they all worked together to create a standard then we would all be better off.

TapMind Your Language

1 Nov 2006 09:24 by Rick

My teachers would have been the first to say that language was not my strong point. In fact, I have the unenviable distinction of having reached the end of formal education without a single language qualification to my name. But as a scientist, it bugs me when people use incorrect words because it conveys incorrect meaning and thus makes the communication pointless or even dangerous.
In the news this morning there were two prize examples. A chief constable from somewhere said that emergency calls this Halloween had been down by a third from the previous year. It a subsequent sentence it was clear that he meant down TO a third. Perhaps this is a mathematical inaccuracy but I think it was more likely to be careless use of words.
The second was an interview with someone responsible for the WHO report on depleted uranium weapons where he said that a contrary research paper was not included because it was not collaborated by other research. Now at best this is meaningless but at worst it implies that he was expecting there to be collusion between independent research projects. Of course what he meant was that the paper was not CORROBORATED by other research; Mrs. Malaprop would have been proud.
In both cases it was the interviewees that made the error under stressful conditions but I would have expected the interviewers to have picked it up and asked for clarification.
Another one that frequently bugs me is the apparent interchangeability of “site” and “sight” in emails but here I blame the reliance on spell-checkers and an inability of most people (including myself) of being able to proof-read their own writing. Having read this, if any of you want to turn the finger back on me for the poor spelling, use of language or proof-reading on this web site then I welcome it—you will be doing a service to other readers; but please point out the necessary corrections in detail else I will never be able to find them.

TapOnce there was .com …

31 Oct 2006 15:52 by Rick

Whilst on holiday in Catalunya, I was surprised to see web addresses ending in .cat. I thought that there were the original .com and friends created in 1985, a few new ones like .info and the two letter country qualifiers but no. On further research there are all these (and how I think they should be used)…

  • .arpa—A special one for technical purposes.
  • .mil—One of the first and reserved for the US military.
  • .edu—Similar vintage for the US universities.
  • .gov—Similar for the US government.
  • .com—early pandering to the commercial world which now ought be reserved for commercial organisations that are international in scope.
  • .org—for those international organisations which are not commercial.
  • .net—for those organisations who are directly involved in the internet infrastructure.
  • .int was created in 1988 for international organisations like Nato.
  • And a load of new ones created in 2000—.info (general), .biz (general), .aero (aero industry), .name (for individuals, clearly assuming that everyone has a unique name!), .pro (for professionals, whatever that means), .coop (for cooperatives) and .museum (self explanatory). The general ones rapidly degenerated into spam wells but I suppose the others may serve a useful purpose.
  • Some later still—.mobi (sites for mobile devices), .jobs (for recruiting), .travel (for the travel industry) suffer similar problems.
  • Some proposed new ones like .kids, .xxx, .africa, .law and many more have failed to gain recognition but may be adopted at a later date.

On top of these are the two letter country codes, which mostly follow the ISO codes + .eu for general European Union interests. .cat for the Catalan language seems to have been accorded special status. It would have made more sense for this to have been .cat.eu but they have pulled off a coup.
There are some anomalies in the country codes as well. For instance the United Kingdom has .uk, but also has the official ISO .gb which would be incorrect and seems not to be used. .su (Soviet Union) is still in use despite no longer existing as an entity.

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