Author Archives: Owen

Key Questions To Consider For Your Startup

Much good advice (from much smarter people) has been written online about evaluating business models (be sure to look at the business model canvas), but in the past few years I’ve seen many ideas fail because the founders didn’t consider the following key questions:

  • How can you defend yourself from potential or existing competitors/copycats when you start to show success?
    • (Non exhaustive list of) good answers: Proprietary knowledge, legal ownership of idea, the community is on your service and wouldn’t swap, it’s a winner takes all market and you’re going to be first.
  • How strong is the competition compared to the size of market of this idea?
    • If the market is large then competition is less of a problem since you can carve a niche.
  • If your product depends on gaining lots of users then what are your viral loops?
  • How is your idea different from what’s on the market? (If you’re a subset of a competitors features then identify why this gives you an advantage they’re missing)
  • Is there a chicken and egg problem? Do you need user-generated content before new users will sign up? How will you overcome this? (This is the biggest struggle of new dating websites)
  • Does your startup suffer from Airbnb problem of being based around introducing users to each other and then taking a cut but struggling from those new relationships then negotiating payment offline?

Considering these and ensuring you can confidently answer each will help steer you away from just a few more pitfalls along your journey.

A Javascript Library For Writing Bliss Online

Blissymbolics (Bliss) is a symbolic language which allows any phrase to be conveyed by combining symbols. Writing Bliss online has traditionally been very difficult since manipulating images and dealing with alignment is difficult.

AnnotatedBliss is a Javascript library which enables Bliss to be written simply within HTML markup. 

Documentation and download information can be found here.

Example Source:

Hello and <bliss symbols=”feeling arrowintobuilding”>welcome</bliss> to the home of <bliss symbols=”language worldwriting”>Blissymbols</bliss>.

Displays as:

Hello and welcome to the home of Blissymbols.

It is my hope that AnnotatedBliss will allow Bliss to be used more widely online and for new resources to be created to promote it’s use. Please note that this library is currently in beta – please report any problems to

Hide Secret Messages In Facebook Photos Using This New Chrome Extension

Secretbook is a Chrome Extension I built as a research project in Oxford University (supervised by Dr Andrew Ker - brief) which allows users to transmit completely secret messages on Facebook. These messages are hidden in photos so they cannot be scanned for keywords by Facebook or read by prying friends.

Download the extension here and then hit ctrl+alt+a on Facebook to activate the secret new functionality. Any user with the correct password and extension installed can then decode the secret message by pressing ctrl+alt+a while looking at the photo in question.

200% zoom of before and after embedding a secret message. Changes are slight enough that without access to the original it would be impossible to visually detect the message.

The extension utilises a technique known as JPEG Steganography to hide secret messages in photos by making many visually imperceptible changes to encode the secret data. This technique has been demonstrated many times in the past although this is the first time software which allows the JPEGs to be recompressed (such as when uploaded to Facebook) without damaging the secret contents has been publicly available.

Steganography tools have traditionally been complicated (and often command line based) so a core goal to this project was to make Steganography easy and accessible so more people can take advantage of the privacy it provides.

Tools to detect steganography have existed for a long time and this extension is also susceptible - the advantage in this case is that 300+ million new photos are uploaded to Facebook every day so any detection process is likely to find a huge number of false positives. In the past walled gardens have always recompressed JPEGs rendering previous steganography tools unusable – that is the true innovation this extension brings.

The goal of this project was to demonstrate a proof of concept of performing steganography on a social networks with JPEG recompression, not to provide total security. Hence this application is only suitable for casual users and is totally useless for serious applications such as terrorism since detection would not be difficult for organisations such as the NSA.

Full details of implementation are given in the following draft document.

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