1595973600

# Introduction for Cyber Security / Technical Professionals:

Some of these sections are meant for parents to have meaningful activities teaching their kids signaling/ciphers. So there’s theory and the use of PowerShell through a 2D array ingestion of for the word search. You can skip over some of the theory and go straight to my Github and review the comments for more usage and ideas. You can go directly to the signaling sections for ideas on how to communicate in an obfuscated manner that would be difficult for SIGINT analysis while combining linguistic crypto.

# What are Ciphers and why use them?

Ciphers are functions either through a form of math formulas or some other form of methods that can be repeated through steps. Ciphers are a small part of the world of cryptography where the primary goal is to hide messages or communications from people you don’t want to know what you’re saying. It also means you only want your messages to only be understood by your intended friend. Ciphers also reveal or unlock hidden messages through a key, something only you and your friend know. Someone without he key cannot unlock the hidden message. As illustrated below, you take the method or steps you want to use to hide or encrypt the message and combine it with as secret (your key). Now the message becomes unreadable until your friend uses that same key to unlock or decrypt that the message:

To further explain for example, you wish to send your friend a message saying: “Are you online?” but you don’t want your other friends to know. You use a cipher and a secret key to encrypt your message that prevents it from view; equivalent to a lock box. Your other friends can’t open the lock box of containing the real message because they don’t have the key. The friend you sent the message to, will have your same key and then unlock the box to reveal the secret message you have sent. This is known symmetric encryption because you both use the same key to encrypt and decrypt the message.

Parents: Ask your child the difference between an encrypted message and a decrypted message?

Tip: Re-enforce the concept of the message in a lock box concept.

# What is signaling and how are signals used?

Signals are any representation that “means” something to you or someone. For instance, speaking to someone; the set of noises and gestures you may make with face and hands all form one or more signals to your friend you’re speaking to. When you write a message on a piece of paper and hand it to your friend, you are sending a signal, and your friend is receiving a signal. The signal is the piece of paper that transfers your message to your friend. You could send a different signal for the next message you want to send through by saying your message to your friend. If you write a letter to your friend, that’s one signal. If you want to walk up to your friend and tell your friend something else or the same thing, that’s another signal. Two distinct signals.

Parents: Ask your child to give you a 3rd example of a signal

# Putting it together: Using Word Search Puzzles for Crypto and Communicating Signals

Let’s get hands-on with using ciphers and signals to communicate those hidden messages to our friend(s). Do you remember how a word-search puzzle works? You find words in a scrambled set of letters to reveal the messages someone wants you to solve. The following illustration is an example of a 15x15 square of letters with the followings that I may want to send to my friends! But before you go “solving” the word search puzzle; I want to communicate the phrase “change security” to my friend. But how do I hide it from anyone else seeing it but my friend?

OK I want to send the message “change security” to my friend without it easily been seen by other friends? Well we have to first use a cipher, as series of steps or math that will take “change security” and turn it into something not readable by anyone else but my friend.

Parents: Ask your child what components are needed to encrypt the message “change security” when I send it to my friend?

Solution: I will need the following components: my plaintext message = “change security”, the cipher (steps to encrypt the message), and the secret key (to unlock the lockbox) for message decryption.

# The Encryption Cipher of the Word Search Puzzle

Great! We have our components identified of what to use to send our message but how do we convert a word search puzzle into a cipher? We don’t. The word search puzzle is an array of 2-dimensions (2D) is actually is the key you’re going to give to your friend so they also have a copy to decode the message. We’re also not going to “solve” the word search puzzle by circling the words. We’re going to use what’s called substitution and transposition as our cipher. Substitution is when you replace a character (letter) or word with something else in its place. A transposition is when you “shift” or “move” a character or word based on a specific offset interval.

A combined example of substitution and transposition cipher method is when you replace the letter “A” with the number “0” or the letter “B” with the number “1” and “C” with the number “2”. We start with 0 because it’s the offset, or position, of the English alphabet letter (26 letters total, but we start from position 0 that ends at 25). The substitution happens because A is no longer “A”, it’s represented by a number. The transposition happens because we’re basing “A” based on its offset position of “0” because it’s the start of the alphabet. Remember an offset means a start from a position, not the “next step” like we do with counting “1,2,3…etc” This is also known as a variant of the Caesar cipher; our example is specifically (ROT-0) which means rotation of 0. The original Caesar cipher was ROT-13.

# How do we apply substitution and transposition as a cipher to the word search puzzle?

If we look at the word search puzzle as a 15x15 square, we can think of it as quadrant (Quadrant 4 specifically) from a math plane and assign each letter within as coordinate pairs. So the first letter in our puzzle, which appears to be “F” we can think of it as the pair, x=0, y=0 (0,0) because it starts at the first position (0 offset) for both the row and the column in the square. This is illustrated below:

Now what would we do if we wanted to encrypt the word “fun” using our word search as the _key _and our coordinate method (substitution and transposition) as our cipher? Let’s start off with the anywhere letter “F” appears.

Parents: Be sure to remind your child that it isn’t important the “solve” the cross word puzzle with specific words, we’re just using it as a shared secret key. If you were to have the child solve the puzzle by just finding words out of it, it defeats the purpose because it provides easy-plaintext readable messages that isn’t obfuscated or encoded. Tip: If your child is wanting to focus on solving the word search, let them solve it. Then when they ask if it’s encrypted or insist that it’s encrypted; you refer back to the prior section on symmetric encryption and explain how another friend or parent could easily read their circled words on the page. Also remind them on the point of encryption (using ciphers) was meant for.

So we know one position of the letter “F” is (0,0) at the top left corner. Let’s find and determine a position for the letter “U” and “N”. Pick anywhere you wish!

#cryptography #cybersecurity #education #encryption #learning #deep learning

1602002446

## Hand Sanitizer in bulk - Get your effective hand sanitizer here

With the spread of various harmful virus globally causing immense distress and fatalities to human mankind, it has become absolutely essential for people to ensure proper and acute hygiene and cleanliness is maintained. To further add to the perennial hardship to save lives of people the recent pandemic of Covid-19 affected globally created the worst nightmare for people of all walks of life. Looking at the present crisis, it has become imperative for human beings to be encouraged to tackle this challenge with an everlasting strength to help protect oneself and their loved ones against the devastating effects of the virus. One thing that stands up between keeping all safe and vulnerable is by making sure that everybody attentively Hand wash periodically to help physically remove germs from the skin and getting rid of the live microbes.

The essence of apposite handwashing is based around time invested in washing and the amount of soap and water used. Technically, washing hands without soap is much less effective anyway. But incase a proper handwashing support system doesn’t become possible around, the usage of Effective Hand Sanitizer will certainly help fight to reduce the number of microbes on the surface of hands efficiently, eliminating most variants of harmful bacteria to settle.

The need has come about for Hand Sanitizer in bulk to save your daily life aptly maintaining a minimum of 60% alcohol - as per the CDC recommendations and approved by USFDA for its greater effectiveness. With the growing demand of people on the move the demand for easy to carry, small, and travel size worthy pouches that are also refillable once the product runs out is the need of the hour. To further make sure that human lives are well protected from these external viruses, it is mandatory for producer of effective Hand Sanitizer to evolve products circumspectly with ingredients that produce not just saving lives but with multiple benefits for people of all ages.

#hand sanitizer #hand sanitizer in bulk #hand sanitizer ingredient #hand sanitizer to alcohol #hand sanitizer travel size #hand sanitizer wholesale

1595973600

# Introduction for Cyber Security / Technical Professionals:

Some of these sections are meant for parents to have meaningful activities teaching their kids signaling/ciphers. So there’s theory and the use of PowerShell through a 2D array ingestion of for the word search. You can skip over some of the theory and go straight to my Github and review the comments for more usage and ideas. You can go directly to the signaling sections for ideas on how to communicate in an obfuscated manner that would be difficult for SIGINT analysis while combining linguistic crypto.

# What are Ciphers and why use them?

Ciphers are functions either through a form of math formulas or some other form of methods that can be repeated through steps. Ciphers are a small part of the world of cryptography where the primary goal is to hide messages or communications from people you don’t want to know what you’re saying. It also means you only want your messages to only be understood by your intended friend. Ciphers also reveal or unlock hidden messages through a key, something only you and your friend know. Someone without he key cannot unlock the hidden message. As illustrated below, you take the method or steps you want to use to hide or encrypt the message and combine it with as secret (your key). Now the message becomes unreadable until your friend uses that same key to unlock or decrypt that the message:

To further explain for example, you wish to send your friend a message saying: “Are you online?” but you don’t want your other friends to know. You use a cipher and a secret key to encrypt your message that prevents it from view; equivalent to a lock box. Your other friends can’t open the lock box of containing the real message because they don’t have the key. The friend you sent the message to, will have your same key and then unlock the box to reveal the secret message you have sent. This is known symmetric encryption because you both use the same key to encrypt and decrypt the message.

Parents: Ask your child the difference between an encrypted message and a decrypted message?

Tip: Re-enforce the concept of the message in a lock box concept.

# What is signaling and how are signals used?

Signals are any representation that “means” something to you or someone. For instance, speaking to someone; the set of noises and gestures you may make with face and hands all form one or more signals to your friend you’re speaking to. When you write a message on a piece of paper and hand it to your friend, you are sending a signal, and your friend is receiving a signal. The signal is the piece of paper that transfers your message to your friend. You could send a different signal for the next message you want to send through by saying your message to your friend. If you write a letter to your friend, that’s one signal. If you want to walk up to your friend and tell your friend something else or the same thing, that’s another signal. Two distinct signals.

Parents: Ask your child to give you a 3rd example of a signal

# Putting it together: Using Word Search Puzzles for Crypto and Communicating Signals

Let’s get hands-on with using ciphers and signals to communicate those hidden messages to our friend(s). Do you remember how a word-search puzzle works? You find words in a scrambled set of letters to reveal the messages someone wants you to solve. The following illustration is an example of a 15x15 square of letters with the followings that I may want to send to my friends! But before you go “solving” the word search puzzle; I want to communicate the phrase “change security” to my friend. But how do I hide it from anyone else seeing it but my friend?

OK I want to send the message “change security” to my friend without it easily been seen by other friends? Well we have to first use a cipher, as series of steps or math that will take “change security” and turn it into something not readable by anyone else but my friend.

Parents: Ask your child what components are needed to encrypt the message “change security” when I send it to my friend?

Solution: I will need the following components: my plaintext message = “change security”, the cipher (steps to encrypt the message), and the secret key (to unlock the lockbox) for message decryption.

# The Encryption Cipher of the Word Search Puzzle

Great! We have our components identified of what to use to send our message but how do we convert a word search puzzle into a cipher? We don’t. The word search puzzle is an array of 2-dimensions (2D) is actually is the key you’re going to give to your friend so they also have a copy to decode the message. We’re also not going to “solve” the word search puzzle by circling the words. We’re going to use what’s called substitution and transposition as our cipher. Substitution is when you replace a character (letter) or word with something else in its place. A transposition is when you “shift” or “move” a character or word based on a specific offset interval.

A combined example of substitution and transposition cipher method is when you replace the letter “A” with the number “0” or the letter “B” with the number “1” and “C” with the number “2”. We start with 0 because it’s the offset, or position, of the English alphabet letter (26 letters total, but we start from position 0 that ends at 25). The substitution happens because A is no longer “A”, it’s represented by a number. The transposition happens because we’re basing “A” based on its offset position of “0” because it’s the start of the alphabet. Remember an offset means a start from a position, not the “next step” like we do with counting “1,2,3…etc” This is also known as a variant of the Caesar cipher; our example is specifically (ROT-0) which means rotation of 0. The original Caesar cipher was ROT-13.

# How do we apply substitution and transposition as a cipher to the word search puzzle?

If we look at the word search puzzle as a 15x15 square, we can think of it as quadrant (Quadrant 4 specifically) from a math plane and assign each letter within as coordinate pairs. So the first letter in our puzzle, which appears to be “F” we can think of it as the pair, x=0, y=0 (0,0) because it starts at the first position (0 offset) for both the row and the column in the square. This is illustrated below:

Now what would we do if we wanted to encrypt the word “fun” using our word search as the _key _and our coordinate method (substitution and transposition) as our cipher? Let’s start off with the anywhere letter “F” appears.

Parents: Be sure to remind your child that it isn’t important the “solve” the cross word puzzle with specific words, we’re just using it as a shared secret key. If you were to have the child solve the puzzle by just finding words out of it, it defeats the purpose because it provides easy-plaintext readable messages that isn’t obfuscated or encoded. Tip: If your child is wanting to focus on solving the word search, let them solve it. Then when they ask if it’s encrypted or insist that it’s encrypted; you refer back to the prior section on symmetric encryption and explain how another friend or parent could easily read their circled words on the page. Also remind them on the point of encryption (using ciphers) was meant for.

So we know one position of the letter “F” is (0,0) at the top left corner. Let’s find and determine a position for the letter “U” and “N”. Pick anywhere you wish!

#cryptography #cybersecurity #education #encryption #learning #deep learning

1593682075

## Which is a Good App Design Practice?

Which is a Good App Design Practice in 2020? Following amazing tips on mobile app design best practices and withdrawing the most typical mistakes will assist designers to create apps.
check out our blog on The Guide to Mobile App Design: Best Practices for 2020 and Beyond.

#which is a good app design practice? #mobile app ui design best practices #app design best practices

1673727660

## Yoha

A practical hand tracking engine.

## Installation

npm install @handtracking.io/yoha

• You need to serve the files from node_modules/@handtracking.io/yoha since the library needs to download the model files from here. (Webpack Example)
• You need to serve your page with https for webcam access. (Webpack Example)
• You should use cross-origin isolation as it improves the engine's performance in certain scenarios. (Webpack Example)

## Description

Yoha is a hand tracking engine that is built with the goal of being a versatile solution in practical scenarios where hand tracking is employed to add value to an application. While ultimately the goal is to be a general purpose hand tracking engine supporting any hand pose, the engine evolves around specific hand poses that users/developers find useful. These poses are detected by the engine which allows to build applications with meaningful interactions. See the demo for an example.

Yoha is currently in beta.

## Language Support

Yoha is currently available for the web via JavaScript. More languages will be added in the future. If you want to port Yoha to another language and need help feel free reach out.

## Technical Details

Yoha was built from scratch. It uses a custom neural network trained using a custom dataset. The backbone for the inference in the browser is currently TensorFlow.js

### Features:

• Detection of 21 2D-landmark coordinates (single hand).
• Hand presence detection.
• Hand orientation (left/right hand) detection.
• Inbuilt pose detection.

#### Supported Hand Poses:

• Pinch (index finger and thumb touch)
• Fist

Your desired pose is not on this list? Feel free to create an issue for it.

### Performance

Yoha was built with performance in mind. It is able to provide realtime user experience on a broad range of laptops and desktop devices. The performance on mobile devices is not great which hopefuly will change with the further development of inference frameworks like TensorFlow.js

Please note that native inference speed can not be compared with the web inference speed. Differently put, if you were to run Yoha natively it would be much faster than via the web browser.

## Minimal Example

git clone https://github.com/handtracking-io/yoha && \
cd yoha/example && \
yarn && \
yarn start

## Drawing Demo

git clone https://github.com/handtracking-io/yoha && \
cd yoha && \
yarn && \
yarn start

Author: Handtracking-io
Source Code: https://github.com/handtracking-io/yoha

1623370500

## Practice Problems: How To Join DataFrames in Pandas

Hey - Nick here! This page is a free excerpt from my \$199 course Python for Finance, which is 50% off for the next 50 students.

It’s now time for some practice problems! See below for details on how to proceed.

### Course Repository & Practice Problems

All of the code for this course’s practice problems can be found in this GitHub repository.

There are two options that you can use to complete the practice problems:

• Open them in your browser with a platform called Binder using this link (recommended)
• Download the repository to your local computer and open them in a Jupyter Notebook using Anaconda (a bit more tedious)

Note that binder can take up to a minute to load the repository, so please be patient.

Within that repository, there is a folder called starter-files and a folder called finished-files. You should open the appropriate practice problems within the starter-files folder and only consult the corresponding file in the finished-files folder if you get stuck.

The repository is public, which means that you can suggest changes using a pull request later in this course if you’d like.

#dataframes #pandas #practice problems: how to join dataframes in pandas #how to join dataframes in pandas #practice #/pandas/issues.