Digital Signage and the Law – Importance of Responsible Installations

It is quite common on many empty city walls and properties to see the words: ‘Bill posters will be prosecuted.’ Irresponsible outdoor advertising has been responsible for legislation preventing the unauthorised use of outdoor advertisements as well as blackening the name of those responsible street advertisers.

A similar problem is now arising with the arrival of outdoor digital signage and much debate and controversy is now centred on the use of this new street advertising.

Critics of digital outside signage claim it is aesthetically unsightly and can cause a distraction to drivers that have led to many authorities in the USA in particular, to question street advertising legislation and to contemplate additional restrictions for digital outdoor signage.

Restrictions that are being imposed on digital signage installations include:

* A limit to the number of electronic billboards and digital signage systems in any given area
* Limiting sign companies from converting traditional print media into digital signage
* Limiting the time and frequency that images and advertisements can change with time limits set on messages so no more than one change in every eight seconds being a common restriction.
* Some states in the USA (Montana to name one) have even banned signage screens from state roads meaning that no signage along roadsides in the entire state can exist (A considerable blow to the outdoor advertising industry that have for decades used static billboards along roadsides and are now unable to convert them to digital billboards)

Some of these measures may seem quite draconian; especially the banning of all roadside digital signage, and many other cities, states and countries may not restrict digital advertising in such an austere manner. However, it is clear that if outdoor advertising companies fail to act responsibly and erect signage screens that could be considered unsightly, dangerous or a nuisance.

As an industry it is important we all act responsibly otherwise our own local councils and authorities may impose similar restriction curbing installations, profit and expansion of the entire outdoor digital signage industry.

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DAB Digital Radio – The Analog Alternative

DAB, or digital audio broadcasting, brought to the radio industry what the digital technology of cellular phones brought to the telecommunications industry–an alternative to analog technology. Using the Eureka 147 format, broadcast companies in Europe and the UK made the shift form analog broadcasting to DAB digital radio broadcasting; the Eureka format became globally standardized everywhere except in the United States.

The United States chose instead to have its DAB digital radio broadcasting formatted in hybrid-digital radio, which make it the only country to have done so, and more or less stopped the adoption of DAB digital radio technology altogether. In the United States, satellite radio has received all the broadcasters’ and broadcasting equipment manufacturer’s attention. Why?

Because satellite radio requires listeners to purchase expensive receivers, and in addition, to shell out the cost of subscribing each month. Radio listeners in other countries must simply raise their eyebrows at the prospect; they receive Eureka 147 and digital radio at no cost.

DAB Digital Radio Features

When the UK decided to make a massive commitment to DAB digital radio in 2001, all of the BBC’s public radio stations, and more than fifty private ones switched their operating systems from analog to the analog and digital hybrid. The radio receivers used to pick up HD audio broadcasts have the capacity to display information relevant to the audio content of the broadcast.

DAB digital radio transmits radio text to the listener, providing tidbits lie the name of particular musical artist when his or her song is being aired, or the plot summary of a radio drama for which the listener may have tuned in a bit late. It will identify the participants in a talk program, or give up to the minute scores for sporting events.

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Digital Signatures and Suppress-Replay Attacks

Digital signatures are seen as the most important development in public-key cryptography. Sun Developer Network states, “A digital signature is a string of bits that is computed from some data (the data being “signed”) and the private key of an entity. The signature can be used to verify that the data came from the entity and was not modified in transit” (The Java Tutorial, n.d.). Digital signatures should have the properties of author verification, verification of the date and time of the signature, authenticate the contents at the time of the signature, as well as be verifiable by a third party in order to resolve disputes. Based on these properties, there are several requirements for a digital signature. The first of these requirements is that the signature must be a bit pattern that depends on the message being signed. The next requirement is declared in order to prevent forgery and denial. It states that the signature must use some information that is unique to the sender. The third requirement is that it must be fairly easy to generate the digital signature. Being relatively easy to recognize and verify the digital signature is another requirement. The fifth requirement states that it must be computationally infeasible to forge a digital signature, either by constructing a new message for an existing digital signature or by constructing a fraudulent digital signature for a given message. The last requirement is that it must be practical to store a copy of the digital signature. Many approaches for the implementation of digital signatures have been proposed, and they fall into the direct and arbitrated digital signature approaches (Stallings, 2003).

The direct digital signature involves only communication between the source and destination parties, and the arbitrated digital signature schemes include the use of an arbitrator. The direct digital signature is created by encrypting the entire message or a hash code of the message with the sender’s private key. Further confidentiality can be provided by encrypting the message in its entirety and adding signature using either the receiver’s public key or a secret key shared between the sender and receiver. One weakness in the direct signature scheme is that a sender can later deny having sent a message. Another weakness is the threat of a private key being stole and sending a message using the signature. Both weaknesses are the primary reason for the arbitrated digital signature scheme. In arbitrated scheme, a sender’s message must first go through an arbiter that runs a series of tests to check the origin and content before it is sent to the receiver. Because the arbiter plays such a crucial role, the sender and receiver must have a significant amount of trust in this arbitrator. This trust in the arbiter ensures the sender that no one can forge his signature and assures the receiver that the sender cannot disown his signature (Stallings, 2003).

The issue of replay attacks is a main concern when dealing with mutual authentication when both parties are confirming the other’s identity and exchanging session keys. The primary issues with mutual authentication lies in the key exchange: confidentiality and timelines. Timelines are susceptible to replay attacks that disrupt operations by presenting parties with messages that appear genuine but are not. One type of replay attack is suppress-reply attack that can occur in the Denning protocol. The Denning protocol uses a timestamps to increase security. The issue here revolves around the reliance on clocks that are synchronized throughout the network. It is stated, “…that the distributed clocks can become unsynchronized as a result of sabotage on or faults in the clocks or the synchronization mechanism” (Stallings, 2003 p. 387). Li Gong states, “…the recipient remains vulnerable to accepting the message as a current one, even after the sender has detected its clock error and resynchronized the clock, unless the postdated message has meanwhile been somehow invalidated,” which is unlikely. If the clock of the sender is ahead of the receivers and the message is intercepted, the opponent can replay the message when the timestamp becomes current. This type of attack is known as suppress-replay attack.

In order to address the concern of suppress-replay attack, an improved protocol was presented. Here are the detailed steps.

1. “A initiates the authentication exchange by generating a nonce, Na, and sending that plus its identifier to B in plaintext. This nonce will be returned to A in an encrypted message that includes the session key, assuring A of its timelines.

2. B alerts the KDC that a session key is needed. Its message to the KDC includes its identifier and a nonce, Nb. This nonce will be returned to B in an encrypted message that includes the session key, assuring B of its timeliness. B’s message to the KDC also includes a block encrypted with the secret key shared by B and the KDC. This block is used to instruct the KDC to issue credentials to A; the block specifies the intended recipient of the credentials, a suggested expiration time for the credentials, and the nonce received from A.

3. The KDC passes on to A B’s nonce and a block encrypted with the secret key by A for subsequent authentications, as will be seen. The KDC also sends A a block encrypted with the secret key shared by A and the KDC. This block verifies that B has received A’s initial message (IDB) and that this is a timely message and not a replay (Na), and it provides A with a session key (KS) and the time limit on its use (Tb).

4. A transmits the ticket to B, together with the B’s nonce, the latter encrypted with the session key. The ticket provides B with the secret key that is used to decrypt EKS[Nb] to recover the nonce. The fact that B’s nonce is encrypted with the session key authenticates that the message came from A and is not a replay” (Stallings, 2003 pgs. 387-388).

This protocol is not vulnerable to suppress-replay attacks due to the fact that the nonces the recipient will choose in the future are unpredictable to the sender (Gong, n.d.).

In conclusion, digital signatures are seen as the most important development in public-key cryptography and include direct and arbitrated digital signature approaches. The direct digital signature involves only communication between the source and destination parties, and the arbitrated digital signature schemes include the use of an arbitrator. Suppress-replay attacks can occur if the clock of the sender is ahead of the receivers and the message is intercepted. This allows the opponent to replay the message when the timestamp becomes current. This issue is overcome by the implementation of a protocol that uses timestamps that do not require synchronized clocks because the receiver B checks only self-generated timestamps (Stallings, 2003).

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Solid State Vs PC – What Are the Best Options For Digital Signs?

Digital Screens are everywhere, some of them look amazing and make us feel better off, some of them just seem like spam, probably an unintended consequence of not taking the time to make sure that the setup works properly and presents the media beautifully. When implementing a digital sign or network to help visitors or sell product benefits it is very important to use the best technology for the job otherwise viewers can quickly get turned off.

Now I don’t know whether you’re in retail, museums or what. But I’m guessing that you want to put up a display to show your visitors/customers great looking content that will either help them make a decision or put them in the right frame of mind for something else you have planned for them. Maybe you’re trying to educate or inspire them. Whatever it is your approaching people and you want to make sure you have the right impact. I’m going to assume you have some amazing content to show them and possibly you set up buttons to make it interactive (these are different topics which I will cover some other time). The question right now is, ‘Should I display it on a PC monitor, a DVD with a TV screen or use a dedicated media player?’. Good question. Let’s look at your options.

Initially you might think a PC is a good direction to go in, especially as we are all pretty much familiar with them. However, they usually come heavily laden with demanding operating systems, so you are going to have to confront issues such as power consumption and noisy fans whirring away once the hard drive gets too hot. There are two main advantages that PCs have in the digital signage arena

The web – There is no other tool that allows a visitor to access the web directly through the interface.
Complex touch screen interactive user interfaces

The down sides to using PCs are that you may experiences crashes and consequently downtime with individual machines or across the network. They can get noisy when the fans start. This is all the more likely in poorly ventilated installations. Both these cause a negative impact to the viewer. Also, the carbon footprint is higher than the alternative, which will also mean higher operating costs. Pretty much the same goes for using DVD Players. It is also worth mentioning that neither PCs or DVD players are really designed to deliver consistent playback over long periods, or to be left playing constantly, although they can be used this way.

So what about dedicated solid state media players. These are becoming more and more popular and sophisticated offering devices from the humble device for playing back looping media to hi-tech network HD devices that make beautiful content soar with software management tools and services. Companies making dedicated digital media players such as Digital View put a lot of resources into building players that deliver results for every aspect of the project from quality to technical capability. Solid state drives are one of the key features offered in many of these models.

Solid state refers to digital storage or media devices that have no internal moving parts. There are a few reasons why this technology solution is exceptionally suited to serving digital signage:

No moving parts – This means that the device is more robust as there are no delicate parts that can be damaged from say dropping the device on the floor. Plus units generate less heat, so don’t require noisy fans, which of course has the benefit of being silent always.
Low power consumption – Typically less energy is required so power consumption can be reduced in some cases very significantly
Fast Data Retrieval – Access to data is typically instantaneous because there are no moving parts. This means that the speed at which data is read is as fast as the controlling device allows. In dedicated/optimized players this is very fast
Reliable continuous playback – with such robust technology, these drives are ideally suited to continuous long term play back and rarely fail

This brief overview of solid state vs PC and DVD player for digital signage doesn’t cover all the issues, but does highlight some important considerations. I hope this helps you to make a more informed decision when it comes to planning a digital signage strategy that will deliver good results.

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How To Digitize A Sewing Clothing Pattern in 5 Easy Steps

The process to digitize a pattern design into a cad system can be very time consuming and expensive due to the point by point process that needs to be follow in order to complete the digitizing process. Following next are 5 easy steps to expedite and complete the digitizing process in a smooth and simpler manner.

1st Step, You need to have a hard copy or tracing of your design on paper. Paper must be flat for accurate piece digitizing and all your tracings should visible and marked with hard lines. Not having visible marks on your pattern pieces will complicate or delay the digitizing process.

2nd Step, Mark information as grain lines and description on every piece to be digitized. Whenever possible mark all your lines with a hard marker and specify what fabric it should be cut in if is it a self material or is it a contrast material how will your pattern piece be cut after it has been fully digitized.

3rd Step, Provide a pattern card along with fabric description. Make sure you provide a list of all the pieces and label each piece accordingly before they get digitized into a computer digitizing system. Not doing so, will create problems when your digitized patterns goes into production and your pieces are all label incorrectly or simply the cutter will not understand what you are trying to do.

4rth Step, Make sure that your pattern or style to be digitized into a cad digitizing system is the correct model, do not mix pieces that do not belong to that particular style, as you will be charged for any extra piece digitized.

5th step, Finally and not of least importance, make sure that the pattern you have provided for digitizing has been approved for digitizing and that all corrections or modifications needed have been applied to it. Modifying or correcting your pattern after it has been digitized is not included in any digitizing process as this will normally be a separate service charge to you.

In addition, Following this 5 easy steps to digitize any clothing design pattern will simplify the digitizing process and time it takes to digitize. You must accurately mark and provide any pattern piece information needed prior to staring the digitizing process and no correction or modification to your pattern piece will be made after your pattern has been entered into a state of the art digitizing system.

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