I remember a time where people would advise to just hash the password with md5 before storing it into a database.
Then md5 became a bad choice because of the rainbow tables (precomputed tables of md5). The concept of salt helped (adding a secret value to passwords before hashing them).
But hash were never meant for encrypting passwords. As KDF. But KDF seems to be better a fit for that kind of task.
See Ty's blog post "please stop hashing passwords". He makes good points and advise using those following KDFs for the job:
Scrypt is the one used in Litecoin by the way.
I've read a LOT of stuff about procrastination. I have techniques:
I think those are all my techniques, I can't really think of any others.
A few months ago I started counting my calories intake, and I lost weight! It's magic. As soon as you start counting the bad stuff, you realize how much you're doing of it.
I've had this idea for quite a long time, a slack counter, that times how long you slack per day. It compares that to the average.
I don't know how to implement that, but a cellphone app would be the best suited I think. We always carry it, so we just have to launch the app and start a timer when we procrastinate. This + a firefox/chrome app that recognizes websites that are "time consumer" to add to your statistics. I'm sure that would help me work more!
When I'm really in trouble, and I can't seem to get motivated, I always take my iPod out and start a 30 minute timer. I do that, and then I find something to work on, anything, and I don't have to be efficient or know right away how I'm gonna work on it. I just have to do it, non-stop, to focus for just 30 minutes. And when the timer stops, I'm usually motivated enough to either keep going, or take a small break and start a bigger timer. I had the idea of implementing a 30 minute timer + a chain system, everyday you can start this 30 minute timer once and if you do work non-stop for 30 minutes while it runs, you will validate a day. Try validating the most days in a row!
Other techniques ?
This article brings 3 good points:
There are two ways to look at any task. You can do something because you see it as a way to end up better off than you are now – as an achievement or accomplishment. As in, if I complete this project successfully I will impress my boss, or if I work out regularly I will look amazing. Psychologists call this a promotion focus
when we say things like “I just can’t get out of bed early in the morning, “ or “I just can’t get myself to exercise,” what we really mean is that we can’t get ourselves to feel like doing these things.
Making an if-then plan is more than just deciding what specific steps you need to take to complete a project – it’s also deciding where and when you will take them.
If it is 2pm, then I will stop what I’m doing and start work on the report Bob asked for.
You have to let go
This article helped/helps me a lot. Every time I fall into a procrastination period (because it's a disease you'll have to live with for the rest of your life :D), I read that article.
I hadn’t figured out the skill that would save me from the procrastination.
Until I learned about letting go.
Learn from the pro
Katia Verresen is a "Mental Energy coach" for CEOs and founders. Here's a nice article about her and interesting stuff she has to say about being efficient, in the zone.
Verresen is a big fan of a tactic called “calendar blocking,” and she encourages her clients to identify the chunks of time on their calendars when they have the most physical energy for work.
The mood you wake up in is critical. Consider it to be the default font for your entire day.
For a marathon runner, people say that the day before and the day before that are the most important. If you mess up with your sleep one day, you'll feel the consequences until two days after.
Verresen actually tells her clients that if they haven’t gotten enough sleep, they shouldn’t take their emotions seriously the next day.
“Mental energy is the ability to separate yourself from your thoughts,” Verresen says. “Everyday, we have millions of thoughts that cause stress, anxiety, depression — that can stall you out in a million different ways — but you don’t have to believe them.”
“The best way to reset your mental energy is to get it up and out into the physical world,” Verresen says. “Screens don’t count. You should put whatever it is that’s bothering you or that you need to get done up on a white board. Write it down and stick it up on a wall.
I sometime stop what I'm doing to do the dishes. It clears my mind.
Verresen advises her clients to block off two slots ranging between 90 minutes to 2 hours every week as mental white space. They need to literally put it on their calendar and make sure they aren’t interrupted or disturbed during this time — ideally they shouldn’t have meetings right afterwards either.
I do this by doing my laundry. I take a paper and a pen with me and I go do my laundry for an hour.
It doesn't seem to be the only appearance of the Gröbner basis on the show:
In the Season 4 opening episode 'Trust Metric' (2007) of the television crime drama NUMB3RS, math genius Charlie Eppes mentions that he used Gröbner bases in an attempt to derive an equation describing friendship.
From wolfram alpha
I've run into this über cool explanation of the Fourier Transform thanks to mtodd's blog
Here's a bit from the introduction:
What does the Fourier Transform do? Given a smoothie, it finds the recipe.
How? Run the smoothie through filters to extract each ingredient.
Why? Recipes are easier to analyze, compare, and modify than the smoothie itself.
How do we get the smoothie back? Blend the ingredients.
And cool examples of what can be done with the Fourier Transform:
- If earthquake vibrations can be separated into "ingredients" (vibrations of different speeds & strengths), buildings can be designed to avoid interacting with the strongest ones.
- If sound waves can be separated into ingredients (bass and treble frequencies), we can boost the parts we care about, and hide the ones we don't. The crackle of random noise can be removed. Maybe similar "sound recipes" can be compared (music recognition services compare recipes, not the raw audio clips).
- If computer data can be represented with oscillating patterns, perhaps the least-important ones can be ignored. This "lossy compression" can drastically shrink file sizes (and why JPEG and MP3 files are much smaller than raw .bmp or .wav files).
- If a radio wave is our signal, we can use filters to listen to a particular channel. In the smoothie world, imagine each person paid attention to a different ingredient: Adam looks for apples, Bob looks for bananas, and Charlie gets cauliflower (sorry bud).
I'm in holidays for a week, easter I think, anyway, I didn't know what to do so I coded the Diffie-Hellman handshake, the ElGamal cryptosystem and the RSA cryptosystem in python.
You can check the code on github here: github.com/mimoo/crypto_studies
tests.py file to see how the classes are used. Here's an extract:
"""Testing Diffie Hellman
# 1. BOB
bob = DiffieHellman()
# G and g are generated automatically
print("G is a group mod %i and of order %i, and the generator g is %i" % (bob.G, bob.G, bob.g))
# We generate a secret and a public key
# 2. ALICE
# We already know G and g
alice = DiffieHellman(bob.G, bob.g)
# We generate the secret key and the public key
# 3. WE CREATE THE SHARED KEY
# Bob and Alice now have the same _sharedkey and the same public (G, g)
README says, it might be oversimplified and not totally correct. I mostly did that to do something in Python and also try to memorize how those systems work.
I've also done a lot of Unity this week-end. And also a bit of WxPython but I don't really like it. I think I should focus on QT and C++.
Those past few months I've been working on a C implementation of a whitebox using Chow et al's paper and the DES algorithm.
It's not done yet but the code is available on github. I also did a C implementation of DES just to get a grip on it, it's available on github as well.
I just did a presentation of the research my team and I did, I think it went pretty well. The slides are here
I've been looking for a summer internship and I haven't really found anything sor far. Although I've had some interviews with some start ups from the Silicon Valley (including TrueVault that really seemed like a good fit for a cryptographer in progress like me :D). But I've been unlucky so far since they're pretty busy, it's demo day-time for those applying to ycombinator there.
Anyway I still have 4 months of holidays this summer and I'm wondering what I'll do if I can't find anything in Mountain View (n_n I really want to go there).
If you know someone, or are interested in a passionate coder and eager learner, you can take a look at my resume here and rush to contact me before someone else does :)
Otherwise I'll spend more time coding personal projects and writing this summer (by the way, Korben, a famous influential blogger in France has written about me and my application 3pages.fr in a blog post. Huge amount of traffic in a few hours, 600 people signing up in a day. I envy his traffic.)
I've used Django for my last project and I found the documentation unclear and the list of things I had to do to code simple things and deploy were... a bit too much for a simple project.
I've glanced at the Flask documentation and have found it über-clear. The syntax seems to be pretty straight-forward as well. I'm really thinking about learning Flask for my next project and putting Django on hold. What do you guys think?
There's also a talk on web2py in the current PyCon. I don't know if it's for me but I really need something I can do quick prototypes on.
Sometimes I wonder if I should go back to PHP and try the new Laravel that really looks super cool :)