Electrical Engineering Stack Exchange
Electrical Engineering Stack Exchange

Questions tagged [security]

107 questions
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4 answers

Why do fire and security systems run at 27.6 V?

I have been looking at buying power supply units for a project, and I keep seeing supplies that output 27.6 V. It's an unusually specific number, so what they are used for, and why is it important that they produce 27.6 V? It appears that these are…
Lucas
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Why are SRAM based FPGA used more than NVM based FPGA?

SRAM based FPGAs need to load the bitstream again after power off. Meanwhile the Non-Volatile based one don't need that. I wonder, why are more experiments and security research done on the SRAM FPGA than the the NVM based one, it seems that the…
Lavender
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Is it possible to jam wireless home alarm systems?

Sorry if this is the wrong community for this question but in my mind, it's the best fit. Please close or move to a more appropriate community if it's off topic. The other day, several home alarm companies came to look at my home to quote an alarm…
Classified
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11
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What is the ideal method of sensing whether 4 points on the bottom of a device are all depressed to indicate contact?

I am trying to place a sensor or switch on each corner of some desktop PCs so that if they are lifted an event is triggered like locking the computer or encrypting it. So far I have considered small round load sensors mounted with adhesive between…
Diagram Alley
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11
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Would an electric fence be able to detect being bypassed?

In the Flashpoint episode "The Farm," there's a scene where you can see one of the officers run a jumper cable from one contact on an electric fence to another, then cut the line of the fence (not breaking the circuit, mind you). Based on context…
Der Kommissar
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A few questions on PIRs and other motion detectors

I grew up incorrectly believing that motion detectors (as part of burglar alarm systems) were designed to detect movement, when in actual fact it is the movement of a heated (like body heat) object which causes them to trip. I also understand there…
questioner
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securely storing and using keys in an embedded system

I'm using a microprocessor - PIC32MZ2048efm144 MCU that receives commands encrypted with a specific key, decrypts them and executes the command. The encrypted commands are stored offline, so I cannot just change the key whenever I want. The key is…
Sonja
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Is there a way to prevent code being read from an MSP430 without blowing the fuse?

I was recently involved at a project in a small company where we had fears of someone taking the code from the master chip, an MSP430F2419, and using it for a competing product. We ended up blowing the JTAG fuses for the first few beta releases, but…
Dom
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Examples of DRM on embedded systems

I'm tasked with implementing a DRM on an embedded system. The device would have a limited number of times which it can run, after which it would be disabled, until it syncs with a computer with an internet to be allowed to run again. For…
alexbb
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How safe is this and should I change it?

I just finished building a project in my house to automate two plugs I installed on the top of my table, but due to laziness I left the ground connections outside the junction box like in the image: For the purpose of the image I left the junction…
DeadSec
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How to save electronic equipment from ants?

Today I brought out my external HDD and it was full of red ants. It took me an hour to remove the ants (it seems quite impossible to remove all of them; some are still inside). I always see some ants are coming out of my laptop. My sister's laptop…
sakibmoon
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Is it possible to read erased flash memory?

In hard disks, a "quick format" does nothing to the actual data on the disk - just clears the FAT (file allocation table), which then appears as a "blank disk" to the user. Therefore, it is fairly easy to ignore the FAT and read that data. Although…
rdtsc
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Large exponentials and 8-bit PIC processors

Does anyone know if 8-bit (PIC) processors could typically handle large exponentials, e.g., 5^15 mod 23, with a reasonable speed? Does doing so result in more cycles than on 16-bit processors? I'm hoping to implement Diffie-Hellman Key Exchange on…
Kar
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How can I embed SmartCard/certificate challenge functionality in an embedded project?

I want to enable secure communication by embedding a certificate chip for a PKI in my embedded system so I can sign outgoing messages and make certificate challenges. I was expecting that there exist particular chips that have these certificates…
Hauke Holtkamp
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How to add security to your Product

I've been trying to build up certain Embedded systems and i wonder how people make them secure. Or else it would have been reproduced well. I know there is an extent to provide security if you are using Controllers like PIC/AVR and well known chips…
Rookie91
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