RSA Algorithm

RSA encryption and decryption algorithm and implementation in C++

RSA is an algorithm used by modern computers to encrypt and decrypt messages. Modern encryption is mostly based on this algorithm.

It is an asymmetric cryptographic algorithm.

Asymmetric means that there are two different keys. This is also called public key cryptography because one of the keys can be given to anyone. The other key must be kept private, Elliptic curve algorithm uses asymmetric cryptography also.

The algorithm is based on the fact that finding the factors of a large composite number is difficult: when the integers are prime numbers, the problem is called prime factorization. It is also a key pair (public and private key) generator.

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Modern Cryptography

Cryptography introduction and different fields

Ancestors had the necessity to transmit information that could not be shared with the rest of the people, although messages may be intercepted and that was the beginnings of cryptography.

Encryption: conversion of information from a readable state to apparent nonsense.

The cryptography literature often uses the names Alice and Bob, who want to transmit information that could not be translated even being intercepted by a third party, Eve.

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Self Driving Car in Unreal Engine 4

Autonomous car: learning and testing process.


Pages: 25

Author: Daniel López Montero


AI is a new field that appeared a few decades ago and has seen unprecedented growth. The AI approach has been used in numerous fields, such as finance, medicine, music, customer service, and transportation. Some of the big challenges we have to cope with are the computing power and lack of documentation. Big companies such as Google and Apple do not share advances in this field, the secretism characterizes this scientific field and thus the information we can get is very restrictive. In this work, we introduce a model of an autonomous car and then examine different algorithms capable of driving the car in a simulated. We also discuss the difficulties we need to deal with such as local minimums, losing diversity, fitness functions, localization, performance, and future applications.


Artificial intelligence, neural network, genetic algorithm, backpropagation, self-driving car.

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Space Elevator

Space Elevator theory and calculations

A space elevator is a proposed type of planet-to-space transportation system. The main component would be a cable (also called a tether) anchored to the surface and extending into space. The design would permit vehicles to travel along the cable from a planetary surface, such as the Earth’s, directly into space or orbit, without the use of large rockets. An Earth-based space elevator would consist of a cable with one end attached to the surface near the equator and the other end in space beyond geostationary orbit (35,786 km altitude). The competing forces of gravity, which is stronger at the lower end, and the outward/upward centrifugal force, which is stronger at the upper end, would result in the cable being held up, under tension, and stationary over a single position on Earth. With the tether deployed, climbers could repeatedly climb the tether to space by mechanical means, releasing their cargo to orbit. Climbers could also descend the tether to return cargo to the surface from orbit.

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Electromagnetic Simulator

Magnetic and Electrosatatic simulator in UE4 and C++

Lorentz force

In physics (particularly in electromagnetism) the Lorentz force (or electromagnetic force) is the combination of electric and magnetic force on a point charge due to electromagnetic fields. A particle of charge q moving with a velocity v in an electric field E and a magnetic field B experiences a force.

    \[\vec{F}=q\vec{E} +q\vec{v}\times \vec{B} \]

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Gradient Descent Algorithm

Mini-batch, Stochastic & Batch Gradient Descent

There are 3 gradient descent algorithms used for backpropagation in neural networks: stochastic, batch and mini-batch.

    1. L_i: loss function (calculate error)
    1. y_i: neural network output (predicted data)
    1. x_i: real output (train label)

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