Cryptography and evil

I was going to write a blog post about mathematical cryptography problems, like good hash algorithms, getting padding right and other juicy problems and contrasting them to social cryptography problems, like trusting keys and blockchain forking. Then I came across this page on Ethereum problems:

While before cryptography was, by and large, a purely computational and information-theoretic science, with strong guarantees built on security assumptions that are close to absolute, once money enters the picture the perfect world of mathematics must interact with a much more messy reality of human social structures, economic incentives, partial guarantees and known vulnerabilities that can only be mitigated, and not outright removed.

That says it better than I could. However I would also have said one of the underlying problems is evil, such as manifested in a 51% attack (that's about one specific attack, but it applies to cryptocurrency generally). Lots of interesting problems to solve!

Ethereum - for when you get bored of bitcoin

A couple of years ago I started reading up about bitcoin, and I put some of what I'd found into Bitcoin - digging deeper.... Whilst what the effect that cryptocurrency will have on the world is interesting I'm finding the potential use of the blockchain (simply put - a distributed pretty much guaranteed trustworthy ledger) more interesting.

Recently I've come across ethereum, which is building its own blockchain for use with smart contracts, such as making sure musicians get paid when you stream their music. Now I find that really interesting.

Sometimes the PR side of such projects isn't too great, but that home page is really good at explaining what it's all about at a superficial level. There are lots of levels below that though.

More another day, including using technology to overcome evil.

Facebook featured image on Wordpress blog posts

Someone recently asked me how we could set the Facebook featured image on our blog posts where there are no images. The featured image is used when you share a page on Facebook. It could be used, for example, on a post where you have an embedded video but no images.

I investigated various plugins which would set it by default for all posts, or you could set it in bulk, but nothing that allowed you to say "use this image on this post". I found another way to do it though. By adding style="display:none" just before the / > on the img tag you can hide an image from a post.


Various social plugins, such as Jetpack, will pick up on this and make it available to Facebook, or in technical terms, put open graph tags on it.

Salesforce and Computing Nostalgia

The results for the Stack Overflow developer survey for 2015 were published recently. Under the section Most Loved, Dreaded and Wanted Tools the top for most dreaded was Salesforce. I tried the web version of Salesforce a few years ago when it first came out. It reminded me of the time when I was working with was DEC Rally (shockingly there is no Wikipedia article I can link to), a fourth generation language that ran on a VT100 terminal (glowing green screen). Define your fields and layout, define data types, create bits of code to run to validate, when focus is gained, when focus has left. Same sort of stuff with a webby interface rather than 80x25 characters. I can see why Salesforce might be dreaded.

If you want more nostalgia then there are a series of Radio 4 documentaries on programming languages.

Moving to Google Apps - our experience

Many other Wycliffe organisations in the Wycliffe Global Alliance have moved to Google Apps, and we decided to join them. Here are my experiences:

Google Apps is free for UK charities, which is an attractive price. However it doesn't mean that it doesn't cost in time. Doing the migrations, plus user training and support all take non-finite amounts of time.

As well as the familiar Google tools, such as Gmail, Calendar and drive/documents, you also get the management interface so you can create and suspend users, turn services on and off and generally manage the stuff.

I've been disappointed with a number of problems that we've had. They are mostly to do with the migration. If you read the forums you find that some of them have been around for a few years with no sign of them being fixed. For example, when you view email that's been migrated using IMAP from Outlook all the dates on the emails are set to the same value. This is because the migration process sets the received date to the migration date. There is a workaround - display the sent date. However, it's a bug - fix it already Google.

There are some Outlook features that are lost when email is synced back to Gmail, but I'm not entirely surprised that Google won't implement features across the board just because Outlook uses them. More information here.

The standard package doesn't include backup so you may want to purchase Google Vault just in case Google loses your email.


If your users already have Google accounts then it copes quite well with multiple accounts in the browser. There are a couple of exceptions - Drive and Blogger require you to log out of all accounts and log into a single one. It's not a surprise that Blogger doesn't do that, as it's a pretty dormant product, but Drive seems like a key part of the offering. Maybe it's being worked on.

On the plus side you do get other Google Apps features, like Drive and Hangouts which are of corporate use. Overall the experience is positive, but if you do decide to switch then allow plenty of time for migration.

Update: I found information about future updates on the Google Apps release calendar and linked newsletters. It looks like there's a fairly healthy amount of work being done on improving Google apps, if not the migration tools.

How hard is it to change your email address?

We're in the middle of moving to Google Apps (I'll write on the experience when we're nearer the end). As part of the process we've taken the opportunity to change our email addresses to use the wycliffe.org.uk domain. So I've gone round various websites changing my email address. The process varies from simply changing a field once you've logged in, to a more complex flow involving verifying the new address. Some sites I couldn't change it, so I had to contact someone to do it by hand.

Some sites have the email address as the username, but you can't change it. I think this is just badly designed. It's not unusual for people to change emails, or for anything that might be work related, for a different person to take over a role. When the old email that hangs around is for someone who has died it just looks bad.

So when designing your site login system, consider how easy you want to make it for someone to change their email address.

I saw a post on a blog, I can't remember which, where someone had wanted to change their email, or retrieve a password on their own site. They were surprised how poor the experience was given the amount of effort they'd put into other parts of their site. Let me know if you've come across that post too and I'll link it here.

IT and Bible translation

An article I wrote on IT and Bible Translation has been published on the Kingdom Code blog. Andy Geers approached me a while back and asked me to write it. I'm just waiting for a flood of email to my inbox now.