I'm not entirely sure why although perhaps because it's a reason to put off job hunting, I've started an online course at Coursera.org on cryptography. We had about 4 lectures on cryptography during the Masters and I enjoyed them so I thought this would be nice revision. I'm not even 2 lectures in with the Coursera material, which is taught by someone from Stanford University and which is supposedly at undergraduate level and it's clear that we barely scratched the surface last year. So what exactly was the Masters for? I'm under no illusions that the university I attended was the equal of Stanford (it was an ex-polytechnic) but postgraduate material should be more advanced than undergraduate shouldn't it?
Anyhow, the Coursera courses are free and on the basis of one week so far (I'm also doing a Gamification course), I'd recommend them.