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When interfacing to third-party web services, one often has to deal with self-signed SSL certificates that trigger verification errors. One workaround is to suppress those errors. (For instance, the Curl tool has the ‘insecure’ flag for this purpose.) However, at Smarking, we found ways to verify such certificates in order to safeguard from Man-in-the-Middle attacks.

Conventionally a web browser relies on a Public Key Infrastructure (PKI) to verify SSL certificates. Every certificate is signed by another (signing) certificate. That signing certificate must be signed by another, in a chain ending on a trusted certificate. This linkage allows a web server…

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At Smarking, we use the Amazon Web Services (AWS) infrastructure. We help organizations improve the efficiency of parking lots, and to do that we need to communicate with their computing systems. However, these organizations, which include hospitals and universities, often run closed private networks. Outside vendors like us may access those networks only through an IPSec-based VPN.

Is it possible to create an IPsec tunnel from an AWS Virtual Private Cloud (VPC) to a network outside of AWS? The use case that AWS supports well is connecting your own on-premises network with the VPC. Thus, in naming components, AWS uses…

It’s been a long time since I read, nay, swallowed the famous novel “Crime and Punishment” by Dostoyevsky (Достоевский). But yesterday, I took part in a meetup discussion on this book, which brought the novel into my focus.

Over the last twenty years, I have learned a few things from Ayn Rand that gave me the tools to see “Crime and Punishment” on the meta level. First, the novel is written in a Romantic style, much like writings of Hugo, Dumas, Jules Verne, and Ayn Rand. In the Romantic literary style, characters such as Edmond Dantes (the Count of Monte…

In the previous article The Tree Table Workstation I have written about how I came up with the Tree Table, and listed all the accessories that I use to make it a full workstation. In this article, I focus on the fact that it is also an alternative version of a standing desk.

In the last years, developers have seen a trend of using standing desks, so as to avoid sitting all day. Some went so far as to create a treadmill desk, on which they walk and work at the same time.

The Tree Table is a new kind…

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The Tree Table

In my previous article titled “The Outdoor Office” I described how I used Roll-a-Table to take my work outdoors. That table allows me to set up virtually anywhere, but it weighs more than 10 lb.. Half of that weight comes from sturdy legs, the other from the body of the table.

As I walked around the parks looking for the perfect spot to set up, I looked at trees. I thought to myself that a tree’s trunk is like a leg of a roundtable. If I could get a table mounted off of this “leg”, the table could be made…

One-sentence summary: I explain why an exponential scale was invented, and how it compares with the older scales based on ratios of integers.

This article is the continuation of the article on the mathematical nature of musical scales. In that article we have used ratios to come up with a division of an octave. We have given Latin names to musical intervals (or ratios of frequencies): octave as 2/1, tertia as 5/4, quinta as 3/2, quarta as 4/3, tone as 9/8, and semitone as 16/15.

In American English the tone, tertia, quinta and quarta intervals are familiarly known as second…

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I got into computers in my teenage years, back in the nineties. I spent a lot of time cooped up in my room for the simple reason that computers weren’t portable. I got a laptop early on, but I still remained at home. Going outdoors didn’t work because I didn’t have portable power. And, there was no way to do email or browse websites without a dialup modem, which had to be plugged into a wall.

After a short while, cell phones appeared. They quickly gained an email function and a basic internet browser. Finally, I was able to go…

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Image attribution: “Many intersecting arrows” by Kalinin Ilya from the Noun Project

This is a technical article for software developers concerned with privacy of users. However, it’s written in a general way, so that a layman can read it.

While many databases store users’ data encrypted, additional metadata is stored in databases in order to look up records. This metadata is not encrypted and can reveal relationships between people.

Let’s say we have two people A and B who wish to store in the database a reference to a datum R. …

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A young man feeds the spirits of his ancestors (photo by Johannes Eisele, Twitter: @johaynz)

Last week I had a chance to appear on a Russian radio station Radio Vera, and I, an atheist, was asked a question about what I think about Spiritism. What is Spiritism? It’s not a fondness for alcoholic drinks (the other meaning of the word “spirits”), but it is a belief in ghosts. Instead of answering what I think about contemporary Spiritism, let’s look what are the origins of such beliefs.

Primitive people had a form of religion already in the prehistoric times. They thought that a spirit inhabited every element of nature. For instance, a mountain has a spirit…

This article discusses technical details about email protocol.

How can one tell that an email belongs to a certain web service? The first thing you can do is look at the “From” address. For instance, if it says “Meetup” then the email is probably from

Another way is to embed a certain keyword in the subject line, usually in the beginning. For instance, emails from Slack have “[Slack]” at the beginning of the subject line.

In addition to these two methods, there are custom mail headers, called by email marketers as X-headers. By convention, they must begin with “X-”…

Boris Reitman

The course of history is determined by the spreading of ideas. I’m spreading the good ones.

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