Koblitz and the Uneasy Relationship between Mathematics and Cryptography

Neal Koblitz published this paper in 2007, examining a couple of different approaches to the area of 'provable security'. It's a fantastic read :D

When I first came across 'provable security', I got a rather uncomfortable feeling.

Sometimes, it is rather apparent when authors deliberately attempt to aggrandise their particular field of interest, mainly by inventing deliberately obscure and opaque notation and conventions to try and convince the novice that the subject is an order of magnitude harder than it really is.

Coming from a pure maths background, I came across little of this in my earlier life, as pure maths is about as humble a subject as you can get.

But, with 'provable security', this attempt at embellishment of what are really rather simple ideas struck me.

This observation is also made in Koblitz's paper, along with words of caution regarding the somewhat rash use of the words and phrases 'proof' and 'provable security', when, from a pure maths point of view, these 'proofs of security' are not absolute, but rather defined with regard to specific notions regarding the capabilities of an adversary.

In particular, in the area I am working in (lightweight cryptography), such 'proofs' are of limited use or relevance.

Don't get me wrong - 'provable security' is elegant in it's own way, and makes for an interesting read (if a bit turgid at times). But there is a real and vindicated danger that it can lure outsiders (and insiders) into a false and dangerous sense of security regarding cryptographic constructions.

On Linear and Differential Cryptanalysis

I get the feeling that there is a possibility of combining (in some way) linear and differential cryptanalysis to form a more powerful strategy or set of strategies.

I actually find it hard to comprehend that Linear Cryptanalysis was not discovered (publicly at least) before 1993 (when Mitsuru Matsui published his paper on attacking DES).

The Vespa PX is back!!!

This made me feel the joy the other day - the iconic Vespa PX from the 70s is re-entering production!

Vespa stopped making it a few years back - I felt unlucky at the time that I was too young to have the money to buy one - but this time round? Ha - it's a strong possibility.

http://www.uk.vespa.com/en_UK/vespa/px/default.aspx

They are just beautiful!

No other 2-wheeled machine can compare...

And, surprisingly, they are still keeping a 2-stroke engine! No eurocrat-induced 4-stroke crap here...

The New Life

It's been ages since I updated this blog, but many things have changed.

I'm now a full-time PhD student in the department of Mathematics, Royal Holloway College, University of London.

I'm working on research into lightweight cryptography, courtesy of the UK taxpayer (via the EPSRC) .

Should I feel guilty about being funded for 3 years by the government and then planning to jump ship and contribute to the Taiwanese economy instead? Maybe, but I don't haha. I really feel the UK is such an unpleasant place to live now on so many levels that I feel very little sympathy towards the plight and future plight of my country.

Mickey and I are happier than ever - she is currently working in Taiwan, but she is moving back to the UK later this year to be with me - something I can never thank her enough for doing.

Well maybe I can, because the plan is for us to move back to Taiwan once I finish the PhD and for us to live there.

I don't think either of us realised how taxing it is to maintain a long-distance relationship.

Even for the strongest and closest couples, maintaining a long-distance relationship is not something that comes naturally - it requires constant attention and care to nurture and keep it alive...

Long-Distance Blues

I forgot how difficult it is to go back to a long-distance relationship. My girlfriend went back to Taiwan a few weeks ago to work and the last few weeks have been some of the most difficult for me.

Minor arguments and misunderstandings become magnified with distance, putting further strain.

Both of us are at important points in our careers - trying to build ourselves up professionally while we are still under 30, and we are prepared to live apart long-distance while we are doing this.

It's not all bad though - we are able to see each other relatively frequently, every 2-3 months or so.

Yu-Hsuan is coming back in about 5 weeks and I will go out to TW for a week around Valentines day.

I can't wait to see her again - I don't really care who reads this - I just want to get this off my chest and say how much I love my girlfriend.

Trip to Ireland

Recently went on a week-long holiday to Ireland with my beautiful girlfriend. By heritage, my blood is about 1/16th Irish, with the last of my ancestors being deported from Ireland to Australia for various crimes they committed around 1850. I've never been able to find out what particular nefarious activities caused their 'relocation' to the antipodes, but someday I'll get to the bottom of it.
Anyway - the first time in Ireland for either Mickey or I.
We left Edinburgh on a Saturday morning (I think), having attempted to sleep in the airport overnight.

Leaving Edinburgh airport:


We stayed in Belfast for one night, then started the 1000 miles of driving that was to follow.
I now harbour a deep hatred of Hyundai cars - the car we hired was a Hyundai Getz 1.1 litre. A terrible machine. Felt so cheap and nasty (presumably because it was), and started shaking badly if 60mph was exceeded. But the worst thing was the fuel consumption - I would expect a supermini with a 1.1l engine to have a decent fuel consumption, but I reckon 40mpg was the maximum we got out of the machine. On returning to Edinburgh, I was such a happy man to get back into my 2.5l Volvo estate - despite the fact it is 14 years old :-D It doesn't start shaking until the dark side of 90mph is crossed. First full day: drove north to the Giant's Causeway and some rope bridge.

Here's Mickey in 'sinister oriental girl' mode :P




I can't honestly recommend Ireland in many ways at all. The North is good (well, I would say that since I'm British haha), but the ROI is insanely over-priced in every way imaginable, apart from diesel fuel, which p*ssed me off since we'd hired a petrol car.

Irish drivers are also insanely aggressive, particularly the women for some reason lol. In Dublin, we witnessed a hilarious encounter between an impatient woman driver attempting to enter a petrol station, and a drunk man who happened to be crossing the entrance when she was attempting to get in. You can guess what happened, but basically it involved much drunken shouting and horn-blaring for the best part of 5 minutes. 'The fighting Irish' haha - so true...

And, just going on the parts we say, the coast of Nothern Ireland seemed more picturesque and beautiful than the south. Here's a photo we took at some random point on the north coast:



After this, we headed SW (into ROI) to the Cavan region (where my illustrious ancestors came from), but not much to see there, apart from Mickey suffering a serious case of rage after seeing the prices in a Chinese takeaway :D

Anyway, then headed to Dublin, wandered around for a couple of days and stayed in a lovely apartment. Visited the Guinness storehouse, and found myself marvelling at the patriotism of the Irish that they can claim to adore a drink so vile as Guiness.



We spent a couple of hours climbing the 'worlds biggest pint-glass' in the storehouse, to claim our pints of Guiness at the top. God, I'd forgotten how bad the stuff tastes. Words cannot describe it - but a photo of Mickey trying it does an adequate job:







After Dublin, we headed down to Galway, staying in an out-of-the-way hostel for a couple of nights to save cash. While there, we took a boat out to the Arran Islands, to be greeted with a little island suffering constant rain and seemingly endless deposits of horse excrement.

Lah... so we kept on going, down to Cork, and visiting the cliffs of Moher on the way. The Irish know how to charge for everything - just to park a car near the cliffs: 6 Euro :'-(

During the holiday, I got thinking about the Irish economy and it's future. The Irish economy seems grossly inflated, with sky-high prices and wages, but without anything underneath. Ireland has gone from being a relatively poor country to a country with a wealthy economy's prices, but having seemingly skipped the steps in between.
New-built but empty buildings abound in the cities, and luxury cars are everywhere, but the underlying economy just isn't there. Large-scale industries are abandoning the country due to the extremely high cost-base there, and the Irish government's refusal to lower the high minimum-wage rate doesn't exactly help.

Photos from the cliffs of Moher:


Eventually drove back round the South coast, stayed across the road from Newgrange memorial for our last night, then back to Belfast and Edinburgh the next day.

Hmmm....not going back until the Irish economy crashes - then will return and extract delicious pleasure from spending as little as possible. Mwahahaha....