What I’ve learned this week: Let’s Encrypt, Python’s lambda and more

It’s never too late to start a tradition. I haven’t been writing blogs lately.

1. Let’s Encrypt

In the ideal world, everyone should be able to do anything without the fear of eavesdropping. 10 years ago, it would be very hard to do this. Personal Computers were not very strong and Internet was slow, therefore HTTPS is reasonably slower than HTTP. Things have been changed. Computers are faster now. Internet speed has been increased exponentially. The only thing that hold HTTPS back is the cost to obtain a server SSL certificate. In my opinion, it should be free because once you have an intermediate certificate that is signed by a root certificate, generating a server certificate is just a piece of cake. Honestly it costs money to obtain an intermediate certificate and maintain supporting infrastructure, and companies usually offset the cost to customers who want to purchase a server certificate.

Actually server certificates have been issued for free for over two years by StartSSL, but the process is not simple. You need to sign up an account, verify your email address, verify your domain, generate a certificate signing part on your server, create a request with StartSSL and wait for your certificate to be signed. The whole process could take up to a day, YMMV. And once it’s expired, you need to go over the whole thing again, except maybe verify your email address.

With the introduction of Let’s Encrypt, things are getting much better. With a simple git clone command, and another command to run the letsencrypt-auto toolkit, once can easily obtain a server certificate in a blink of an eye (no, actually it takes about a minute). And renewing a certificate could be done using the same procedures. Simple and sweet.

Instruction to obtain a certificate.

2. Change iPhone’s battery

Turns out it’s not that hard to change an iPhone’s battery. I’ve been reluctant to do this because I don’t have any idea what to do, and the fear of bricking my iPhone. Until recently, when my battery only lasts for half a day, I knew I have to do this. I purchased the battery replacement kit from ifixit. It took me half an hour to do everything, but I believe you could do much faster because my hands were sweating a lot during the whole process.

3. Bitcoin

“Private Blockchain” is a joke. Blockchain is nothing without Bitcoin. Look at almost every altcoins have been in existence. Each altcoin has its own Blockchain. Banks could easily create their own, or shared Blockchain. But it will not be decentralized and secured. Take a simple private Blockchain maintained by a Bank for example. How much computation is enough to secure its Blockchain? What would happen when someone gained access to one of the mining node? The idea of Blockchain with rollback is absurd, and no difference than shared databases that Oracle and MySQL and IBM have been doing for decades. Without Bitcoin, there will be no incentive to secure the blockchain.

One of the reasons banks and companies are trying to separate Blockchain and Bitcoin is that they don’t want to “associate” their image with the bad image of Bitcoin. Bitcoin has been associated with crime, ransom, drug dealer, terrorist, money laundering but Bitcoin is much bigger than that. Anything bad that can do with Bitcoin can do with Cash. In fact, unlike Bitcoin, Cash leaves no trace or trail of what happened. But everything happen to Bitcoin is recorded permanently on Blockchain.