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Microcontroller: Arduino
Published in Volker Ziemann, A Hands-On Course in Sensors Using the Arduino and Raspberry Pi, 2018
It is possible to interface nearby hardware using infrared (IR) light, which is used in TV remote controls to send information from the remote to the TV to change channel or volume. Incidentally, even the first generation Lego™ Mindstorm microcontrollers communicated in this way. The communication is based on an IR diode using a wavelength of 940 nm and modulating the light at a rate of 38 kHz. Sending bursts of modulated light represents either a LOW or a HIGH signal level and is used to emulate an RS-232-like protocol at low baud rates such as 2400 baud. Another protocol is RC-5, which is commonly used in TV remote controls. Receivers such as the TSOP38438 have optical filters built in and are sensitive only to a narrow band of wavelengths around 940 nm. Moreover, they demodulate the 38 kHz carrier frequency and only deliver a 3.3 or 5 V signal on their output pin, making them very easy to interface.
Network Security
Published in Mário Marques da Silva, Cable and Wireless Networks, 2018
The Blowfish algorithm is another symmetric cryptographic algorithm. It presents a 64-bit block size, with a variable key of length up to 448 bits, being easy to implement by software. The Blowfish algorithm was developed as an alternative to DES. Nevertheless, its encryption capabilities are much below those of the AES. Finally, the RC5 is a very attractive cryptographic algorithm because of its simplicity. Initially developed by Ronald Rivest, the RC5 corresponds to an update of the previous RC4 version. Note that the acronym RC (in RC5) stands for River Cipher. The RC5 has a variable block size of 32, 64, or 128 bits, whereas the key length is fixed to 255 bits. The RC5 is currently used as session (symmetric) key by combined protocols such as SSL or TLS.
Secured Model for Internet of Things (IoT) to Monitor Smart Field Data with Integrated Real-Time Cloud Using Lightweight Cryptography
Published in IETE Journal of Research, 2021
RC5 is a basic block cipher in cryptography. Ron Rivest developed it and examined by RSA Laboratories. A unique benefit from RC5 is the high use of data dependent rotations. RC5 has a variable word size, a round and a hidden variable length key. RC5 has three operations: XOR, addition and rotations. Rotation is continuous and variable rotation was n't linear for most processors. Rotation depends on the key as well as the data. RSA Laboratory has been analyzing it with a 64-bit block for some time. The numbers look really good after five rounds.