With norbt you can prevent the harvesting of your e-mail by not exposing your email address directly.

How: Create a norbt containing your email address or contact details and publish the link to your norbt instead of your email address.

With this solution the spambots don’t have direct access to your email. The only way to get your email is to follow the link and answer the question which the crawler does not know how to answer.

The answer may be trivial, like “What’s my name?” or “What’s my website name?” to stop robots. Or something more complicated to limit access to a smaller group of people, like “What’s my pet’s name?” or “What’s my Nickname?”

As a plus you will get information regarding who has accessed the link and who has answered the question (seen your email). You can find more info on tracking your norbt visits.

Example: In norbt.com we have a link to our contact data instead of our email: contact us (https://norbt.com/TWPM5F).

You may also be interested in: email signatures with norbt

What does it look like?

This is how the data URI for our logo will look like:

data:image/png;base64,iVBORw0KGgoAA .... 5ErkJggg==

The (….) is missing base64 data representing the image.
This is the image embedded as Data URI:

You could do view source code for this page to view the whole data URI for our logo.

Hacking with Data URI schema

Lots of interesting things can be done with Data URI schema. The main purpose on the net seems to be to limit the amount of hits required to load a page by embedding the images inside your html or css with data URIs.

There are other interesting usages which you can easily try.

Image in URL shortener

You can send an image via a URL shortener. You just give your data URI for your image to the URL shortener service instead of a URL. For example, if you had a tinyURL pointing to a Data URI instead of a URL, the link would go directly to the image (a Data URI with the image).

Example: http://tinyurl.com/y9auh64 (this may not work properly in some browsers, tested in FF3.6 and Opera10. In Chrome you may have to resubmit the redirected URL by moving focus to URL and pressing enter. We have not tested with IE8).

You can store your images as text anywhere as Data URI. You can send emails with just the appropriate link to the image.

These are just some of the many uses of Data URI.

Norbt.com usage of Data URI

In norbt.com we use DataURI to provide a link to download files inside your norbt, and to provide a preview of the images inside your norbt.

By using DataURI that are generated in the browser, the decryption and display of the message happens in the browser without server intervention.

IE Limitations

As you may be able to guess, Internet Explorer 8 limits the size Data URIs to 32K.  Hopefully this limit will disappear with Internet Explorer 9.

We think that if it wasn’t due to the poor support of Internet Explorer for Data URI, they would be a lot more popular. It would probably make web pages more interesting as well, because more people would be inclined to use this capability.

If you or your users insist on using IE, we provide an applet that allows you to download the file from the browser, without server intervention. It works, but it adds an additional step that is not necessary in most modern browsers.

The users have spoken!!! Now in norbt.com  you can add files inside your norbt’s encrypted content. The files that you add to your norbt are encrypted and decrypted in the browser same as the text.

How to add files

To add a file you just use the add file section under your norbt’s text in the creation page. You will be prompted to select the file to add. The file will be added to your locked data section. The file has not been sent to the server yet, it has just been transfered from your computer to the browser.  When you press send both the text and file will be encrypted together using your answer and that encrypted data is sent to our servers.

How files are viewed

When a user gives the correct answer for a norbt, the encrypted data for that norbt is downloaded from our server. If the norbt has files associated with it, the encrypted data includes those files encrypted inside. Once the user has the encrypted data for your norbt, she decrypts the data on her browser. If the data contains files, those will be shon as part of the data displayed. If the files are images, the image and a link to download the file will be displayed. If the files are not images just the download link will be displayed.

You can view the example above at https://norbt.com/NORBT

Subscriptions

As we explained in some other articles, recently norbt.com has adopted a fremium policy to try and cover the cost of running the service.

By default the maximun size for your norbt is small.  It’s about 32KB, the size of a small picture (may be 200×200 pixels) or a long text file.  For those users who would like to include larger text or image files, this functionality is available in all of the subscription packages. The lowest subscription includes 400K per norbt for 1.5$/month.  Log in to see the subscription options.

Enjoy the new functionality and keep those comments coming!

A custom ID is an ID chosen by the user at the creation of the norbt. This id will be part of the URL to access that norbt.

Example:    http://norbt.com/MY_OWN_ID.

Custom IDs are useful because they are easy to remember and may have meaning for you and those accessing your norbt.

How to create a norbt with a custom ID

You will need to have or create an account (username/password) and subscribe to gain access to the custom ID function.

When you create a norbt, you can select to use a custom ID. Norbt.com will let you know how many custom IDs you have left to use.

Examples:

Signature email with custom ID

We wrote a couple of articles on the advantages of using norbt in your email signature. If your email signature has your name, it will be easier to remember and access. For example John Smith could use https://norbt.com/JOHN_SMITH. You could even use it in your business card.

Directions to your home or office

Use an easy to remember ID for the directions to your home or office. https://norbt.com/JOHN_HOME

In general you can use custom IDs any time that you want an easy to remember and easy to communicate URL.

Disclaimer, not a free feature

Recently norbt.com has adopted a fremium policy to try and cover the cost of running the service. With these new subscription packages, we hope to be able to give something back to the open source community without which this service would not exist.

This feature is only available to subscribers. Currently the minimum subscription that allows you to use this feature costs a whopping 1.5$/month!  Come join our community and help make norbt.com a better service.  Thanks for your ongoing support!

Do you have any other examples of where a norbt.com custom ID might be useful? Leave us a comment to let us know!

In this post we’ll explain how you can control access to your norbt by limiting the number of times that norbt.com will serve your norbt’s encrypted content before the content is blocked to new views.

In our previous post we explained how you can track visits on your norbts . It may be useful to read it to understand better how blocking works.

Why would I block norbts?

There are multiple reason why you may want to block a norbt but some examples that come to mind are the following:

One to one private email

You want to send an email that should only be read once by the final recipient. By setting the number of visits to 1 you are telling norbt.com that the encrypted data should only be served once. Only the first person that access your norbt and answers it correctly gets access to the norbt’s encrypted content.

Challenge with a reward for the first X people to view

If you are doing a challenge where you give a reward to the first X people who answer your question correctly, you could control that by limiting the number of views of the encrypted content to X.

My own private norbts

If you have private norbts with information that only you want to access, you can block them when you are not using them to stop people from trying to guess your answer.

Outdated norbts

If you have norbts that you are not using right now, but may use in the future, you may choose to block it now and un-block it in the future when you need  it. If you delete a norbt you will be losing the ID associated to it, so you may consider blocking it instead to keep the ID.

How to block your norbts

To limit the number of times your norbt can be opened you have to go to the edit/manage page for your norbt. To do that click on the manage norbt in your norbt’s view page. You must be logged in as the owner of the norbt to view the manage button.

Once you are on the manage page for your norbt,  select the view control tab. There you have two options: block the norbt right now using the checkbox or select the number of times that your norbt can be opened before it blocks.

If you select to enter a number in max. views. The norbt encrypted content will not be served by the server once the max views number has been exceed. If the norbt in question has already been served that number of times or more, it will be blocked automatically – the result will be the same as if you had chosen to mark block access.

Note that when you limit the number of times that encrypted content will be served, your requests as a owner of the norbt do not count towards blocking.

Find your blocked norbts

Finding out which of norbt’s are blocked is easy. In your norbt’s page, those norbts which are  blocked appear with red stripes on top of their id.

You can click on any id to go it’s specific view page, and from there to the id management page and change the view control fields if you want to un-block it.

How your blocked norbts are seen

When a norbt is blocked the norbt’s visitor gets a message (see the image below). The user sees the title and the question of your norbt. The user doesn’t get the option to answer the question and view the content.

Some security details

The block feature is controlled by our server, even if you bypass the ui (user interface) and send the right answer to get the encrypted content, our servers will check if the norbt is blocked and if you are the owner of the norbt to know if it should serve the norbt’s encrypted content.

For more details about security see our security page.

We hope you find this functionality useful. We’ll keep on working to improve your experience at norbt.com. Thanks for your support.

To track your norbt’s visits, just sign in with your user. Once signed in, you will see a list of all your norbts. This list has a counter on the right side of the  screen to let you  easily see how many  times each norbt has been viewed (it will  show up like the “45 views” image to the right of this text). It also lets you know how many  times you, the  owner, has viewed the item versus someone else.

For more details on a specific norbt you can click directly to your norbt’s view page. At the bottom of this page you will see a list with the details of when and who did what with your norbt. Only the owner of the norbt can see these details.  For an example of how this looks see below:



On your norbt’s view page, you can see when a user requested your norbt (view question) and when she/he provided the right answer and opened your norbt (view data).

Once you have a user, you can Sign in and manage all your norbts.

This is usefull for multiple reasons:

• you control all your created norbt under a single user.
• your username (which you choose) is easy to remember (not like your norbts id)
• you can view all your norbts in on place (your user page)
• you have only on password (your user’s password) to manage all your norbt. You do not need extra passwords for each new norbt
• New norbt creation is faster and easier signed in as your user. When creating a new norbt, you don’t need to answer a captcha and you have 4 fields less to fill up

You can easily add norbts that have already been created by you to your user bu signing in, going to the norbt you want to manage, clicking on the manage your norbt, and selecting the “own this” tab.

We’ve been working under the radar preparing a bunch of exciting features:

• Create a user to manage all your norbt’s (no more captcha’s!).
• View a complete list of visits to your norbt including who was able to open it.
• Check your new user page to have a quick view of all this data.
• Block your norbt’s or limit the number of times it can be opened.
• Get YOUR_CUSTOM_ID id’s!

And finally:

• Add files to your norbt’s! (Yes, they’ll be encrypted in your browser too).

When you create a norbt, if you specify an e-mail address, you’ll receive a message with some extra instructions and links to directly share your norbt on twitter and facebook:

Once, a norbt is already created, you can still post your norbt via the management tools:

Finally, facebook and twitter may request your consent to complete sharing your norbt.

You may want to play a game with your friends to see if they know the answer to your question. You may want to organize a party for those who know the name of your dog. Or you just want to tell something to a subgroup of your followers (you are filtering that something to an in group with your question/answer)…

Start sharing norbts on Twitter or Facebook now, create a new norbt.

We have changed from Hashing to MAC‘ing. We have updated the security page to reflect the current implementation of norbt. You can find the previous content at security0.

A strong norbt starts with a strong answer.  Remember to think about how easy it is for a person or a computer to guess your answer in order to determine how easy/difficult your norbt is.