Tag: break

Posted in Life & Happiness

The Art Of Doing Nothing

Posted on by Jinavie

Our brain thrives on stimulation. We constantly look for distractions, pushing ourselves to always be doing something productive or active. With modern technology such as computers and mobile phones, we have even more ways to use our free time to learn, work and communicate with others (not to mention procrastinating).

However, important as it may be to stay productive and to take action, we seem to have forgotten how to do nothing. There is rarely a moment nowadays when we are truly doing nothing. On our commute to work, we catch up on social media or listen to podcasts. In between tasks, we upload photos or send messages to friends to stay connected. When we have finished our work and chores for the day, we will “unwind” with a show or movie. Even on the toilet, we use our phones to constantly engage our mind.

As much as our mind loves to be stimulated, it also needs rest to process the abundance of information it absorbs during the day. Otherwise, stress starts to pile up from the rushed pace of life and it manifests as crankiness and fatigue. We don’t feel truly rested because when we are supposed to rest, we continue to overwork our mind. What we need is to take five, space out and daydream.

Daydreaming is considered by society as a negative thing. When kids daydream in class, they are told off to focus and do their work. When adults daydream in their own time, others criticise them for being “lazy” and “dull”. It is the direct opposite of what society sees as productivity, where something is created through work and action.

But there is much evidence to suggest that daydreaming has real benefits to your physical and mental health. When you are daydreaming, your body lets its guard down, slowing your brainwaves, heart rate and breathing. Your brain uses that time to consolidate learning, solve complex problems and take inventory of your thoughts and feelings.

Because you have detached yourself from surrounding sensory stimuli, the brain has space to explore the inner workings of your mind, such as your creative side, and coming up with original thoughts. This moment of pause lets your body and mind refresh, allowing it to work more efficiently in processing the past, being mindful of the present and planning for the future.

So unless you absolutely have to be somewhere doing something important right now, take five minutes, put your phone or computer away, look out the window and space out for a bit, letting your mind wander to wherever it pleases. Don’t let anything or anyone distract you and don’t care about what others will think of you.

Lay your weary head to rest and refresh yourself. You deserve a break.

Posted in Life & Happiness

The Luxury You Cannot Afford

Posted on by Jinavie

The night sky looks darker than it is because the bright moon and stars offer contrast. Similarly, bright colours truly “pop” in a background of dark, simple tones. A tiny pinch of salt brings out deeper, sweeter flavours in chocolate milk and watermelon because it offers a contrast in tastes. Contrast allows us to experience something at a greater level.

Happiness is much the same. Some of our happiest memories are from when we enjoyed luxuries we could not afford. An example would be eating out at a nice restaurant when your budget is straining. You know that rationally, you should not be doing that as you need to save money, but emotionally, you know that this is one of the few cases where money really does buy happiness.

The greatest luxury we cannot afford most of the time, is time itself. All of us lead such busy lives that we lack the free time and energy to indulge in what we are passionate about: hobbies we enjoy, sleeping enough or spending time with people we love. However, this is exactly the time we need to set aside a small break. Ironically, the busier life gets, the more vital it becomes that you stop for a moment and take care of yourself.

Whether it be spending a couple hours having lunch with a friend, or sitting down for half an hour to write in your journal, or singing a song on your guitar for ten minutes, breaks are essential. Even if you feel like you cannot spare a single minute, take five minutes to sit down with a cup of coffee, not doing anything productive, just watching people passing by on the streets. Better yet, lie down on the grass and stare into the blue sky for a little while.

When you look back on your life in ten, twenty years’ time, you will not be savouring the moment of working twelve hours straight without food. You will reminisce on how you spent one evening away from studying to play board games with your friends, but still passed the exams because you were refreshed the next day and could study more effectively.

Happiness is not a grand achievement, but a state of mind. It cannot take root in an overworked soul that is torturing itself. Enjoying the luxury of a break when you think you have no time is one step towards breaking the miserable cycle that our busy lives place us in.

So go on, take five and treat yourself.

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Posted in Life & Happiness

Six Month Break

Posted on by Jinavie

Imagine if you will, that you could drop whatever is happening in your life and have a six-month break. No matter what you are doing – studying, working, preparing to get married – you are allowed to forget about your life and have six months off. During this time, you may go wherever you want and do whatever one thing you have always dreamed of doing as a profession. 

Whether you want to be a walking tour guide in Europe, a scuba diver in the Caribbean islands or a professional gambler in Las Vegas, you can be it. Furthermore, there are no consequences of your break (i.e. you will return back to your normal life afterwards as if it did not happen) and you do not have to worry about skill levels (i.e. you will be at the perfect skill level for your job before you start).

Now that we have set up the perfect “break”, what will you choose to do with it? This question may seem simple, but it helps you search deep inside you for what you truly want in life. Too often in life, we have to set aside our dreams and aspirations just to survive reality. In such a world, telling people to “do what you love” or “chase your dreams” can sometimes seem ignorant as many people do not have the luxury of doing so.

That being said, there is no harm in dreaming – in imagining a world where things could be different and you could do what you really wanted to do. Even if you couldn’t take six months off to chase your dreams, perhaps there are other ways to live a little happier. If your fantasy was to be a barista in Italy, learn to make coffee using a filter. If you dream of being a rap star, spend five minutes of every day writing down some sweet rhymes on a notebook.

Dreams will make your life happier one way or another. All you have to do is give your dream a chance. So what is your dream break?

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Posted in Simple Pleasures of Life

Simple Pleasures of Life #14

Posted on by Jinavie

Taking time off to do something fun when you can’t afford to.

This is most relevant to my life right now with my O&G OSCE (clinical examinations) on Friday, short cases (biggest clinical exam of med school) next Tuesday and two gigantic exams (testing us on literally everything we learnt in med school) the week after that all crashing down at once. The sheer pressure of all of this is really pushing all of us (5th year med students) to a point of anxiety, depression and insanity, and without some way to relieve that stress somewhere, we’d probably end up jumping off somewhere tall or go on a shooting spree.

I personally believe human beings feel the happiest when they are enjoying a luxury they cannot afford. For example, having a nice dinner out once in a while even though your budget is straining. The same applies to time. No matter how busy life gets, just stop what you’re doing and take some time for yourself. Whether it be spending a couple hours having lunch with a friend, playing card games for half an hour, or singing a song on your guitar for ten minutes. Hell, go to the park and lay on the grass for even five minutes, doing nothing but staring into the blue, blue sky. Trust me, it will make a huge difference to your mental health and work productivity.

Here’s an analogy from an old ARK post:

There are two clocks: a still clock and a clock that is always a minute late.
Which clock is more accurate?

The answer is the still clock – it tells the correct time twice every day, but the other clock is always wrong despite the fact that it constantly ticks.
Sometimes when life gets you down, it is better to stop and rest instead of trudging on forever, always out of sync.

(Source: https://jineralknowledge.com/two-clocks)

Posted in Science & Nature

Cryptography: Kasiski Examination

Posted on by Jinavie

The Kasiski examination can be used to attack polyalphabetic substitution ciphers such as the Vigenère cipher, revealing the keyword that was used to encrypt the message. Before this method was devised by Friedrick Kasiski in 1863, the Vigenère cipher was considered “indecipherable” as there was no simple way to figure out the encryption unless the keyword was known. But with the Kasiski examination, even the Vigenère cipher is not safe anymore.

The Kasiski examination is based on the fact that assuming the number of letters of the keyword is n, every nth column is encoded in the same shift as each other. Simply put, every nth column can be treated as a single monoalphabetic substitution cipher that can be broken with frequency analysis. Ergo, all the cryptanalyst needs to do to convert the Vigenère cipher into a Caesar cipher is know the length of the keyword.

To find the length of the keyword, look for a string of repeated text in the ciphertext (make sure it is longer than three letters). The distance between two equal repeated strings is likely to be a multiple of the length of the keyword. The distance is defined as the number of characters starting from the last letter of the first set of strings to the last letter of the second set of strings (e.g. “abcdefxyzxyzxyzabcdef” -> “abcdef” is repeated” -> distance is “xyzxyzxyzabcdef” which is 15 letters). The reason this works is that if there is a repeated string in the plaintext and the distance between these strings is a multiple of the keyword length, the keyword letters will line up and there will be repeated strings in the ciphertext also. If the distance is not a multiple of the keyword length, even if there is a repeated string of letters in the plaintext, the ciphertext will be completely different as the keyword would not match up and be different.

It is useful recording the distance between each set of repeated strings to find the greatest common factor. The number that factors the most into all of these distances (e.g. 6 is a factor of 6, 12, 18…) is most likely the length of the keyword. Once the length of the keyword is found, then every nth letter must have been encrypted using the same letter of the keyword. Thus, by recording every nth letter in one string, you can obtain what is essentially a Caesar cipher. The Caesar cipher is then attacked using frequency analysis. Once a few of these strings (of different positions on the ciphertext) are solved, the keyword can be revealed by checking the shift key against a tabula recta (e.g. if a certain string of nth letters is found to have been shifted 3 letters each, then the corresponding letter in the keyword must be “D”, which shifts every plaintext letter by 3 in the Vigenère cipher). When the keyword is deduced, every message encrypted using that keyword can now easily be decoded by you.

Although the Kasiski examination appears to be complex, attempting to try it reveals how simple the process is. Thus, it is useful to try encrypting a message using the Vigenère cipher then trying to work out the keyword using the Kasiski examination. Much like the frequency analysis, it is an extremely useful tool in the case of needing to break a secret code.

Posted in Science & Nature

Cryptography: Vigenere Cipher

Posted on by Jinavie

It has thus been proven that the Caesar cipher, the pigpen cipher and any substitution cipher can be simply broken using frequency analysis. The basis for this is that each letter or symbol can only represent a single letter, meaning that letter frequencies (e, t, a, o…) are directly translated onto the cipher language. Ergo, by making each letter represent more than one letter, the letter frequencies can be masked and an additional level of security can be added to the cipher. This is called polyalphabetic substitution and it is the basis for a type of cipher known as the Vigenère cipher.

The cipher was first conceived in 1553 by Giovan Battista Bellaso and has been improved since. It is famous for being rather simple to use despite the difficult to decipher it at a beginner’s level. This trait earned the cipher the nickname “le chiffre indéchiffrable”, which is French for “the indecipherable cipher”.

The Vigenère cipher can be thought of a stack of Caesar ciphers (essentially a cipher within a cipher), where each letter is shifted by a variable key (in a normal Caesar shift, every letter is shifted by the same key). This is achieved by the implementation of a keyword and a table called a tabula recta. A tabula recta is simply a grid made from 26 rows of the alphabet, each row of which is made by shifting the previous one to the left. This table essentially shows all the possible outcomes of a Caesar shift.

Now, let us try encoding a message using the Vigenère cipher. The message “attack at dawn” is encoded using the keyword “nothing”. Ideally, there should be no repeating letters in the keyword for the sake of security. Therefore, if there are any repeating letters, just remove the repeated letters (e.g. “crocodile” -> “crodile”). First, repeat the keyword until it matches the number of letters of the message (e.g. “attackatdawn” is aligned with “nothingnothi”). Then, use the tabula recta to encrypt the message. The rule of thumb is “key-row, message-column”, meaning that the row of the tabula recta starting with the letter of the key is matched against the column starting with the respective letter of the message. To take the first letter as an example, the key letter is “n” and the message letter is “a”. The letter corresponding to where the “n” row and “a” column meets is “N”. If this rule is followed for each letter, the encrypted message becomes: “NHMHKXGGRTDV”. Although it takes some effort to find each letter on the table, the message becomes “indecipherable” to a beginner cryptanalyst as frequency analysis becomes useless. For example, the repeating letter “H” can represent either “t” or “a”. The longer the keyword is, the more secure the Vigenère cipher becomes.

However, the Vigenère cipher is not indecipherable. Next, we will look at a cryptanalysis method called the Kasiski examination that attacks a polyalphabetic cipher such as the Vigenère cipher to gain access to the keyword.