Recent content by Carceri

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Dead harddisks?

Thanks for the replies. I will just see if the disks works with a new PCB, in which case the RAID array should work as well. I assume that either all data can be read or no data can be read, in which case I have to use the backup. The RAID controller does not care how the discs are connected...
- Carceri
- Post #10
- Jun 4, 2007
- Forum: Computer Building
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Dead harddisks?

There have been no thunderstorms here in the last few weeks. I had another computer running at the same time on the same wall outlet, and that just kept on running when the other computer suddenly turned off. However, it is a small ITX motherboard with an external 12V PSU, so that might have...
- Carceri
- Post #7
- Jun 4, 2007
- Forum: Computer Building
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Dead harddisks?

They are definitely fried. One of them does not show any sign of damage, but I just tried removing the PCB on the second drive, and I immediately recognized the smell. A chip on the PCB (SMOOTH L6284) has was black on one side, and had scorched the PCB as well. I assume that the second drive...
- Carceri
- Post #5
- Jun 4, 2007
- Forum: Computer Building
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Dead harddisks?

Western Digital WD5000KS
- Carceri
- Post #3
- Jun 4, 2007
- Forum: Computer Building
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Dead harddisks?

Last night my computer suddenly turned off all by itself. I tried to start it again, but nothing happened. I disconnected everything except the ATX power connector and the system turned on, although I didn't even get into BIOS. I found out by trial and error that if I didn't connect the 8 pin...
- Carceri
- Thread
- Jun 4, 2007
- Replies: 9
- Forum: Computer Building
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Java question

While Java has some special means of communication for different purposes (for example Remote Method Invocation (RMI)) most communication is done over TCP or UDP sockets. Here is doesn't matter on what platform the process in the other end runs on. If a reply is not received over the socket in a...
- Carceri
- Post #2
- Aug 30, 2002
- Forum: Ask a Technical Professional
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Primes in P

No, I haven't stated what the running time of the probabilistic algorithm for primality testing is, but if it fails with probability 1/2 on a composite number, running the algorithm X times the probability that it will still accept a composite number as a prime is (1/2)^X. As you can see X needs...
- Carceri
- Post #13
- Aug 10, 2002
- Forum: Ask a Technical Professional
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Primes in P

And just to clarify: The paper describes an algorithm for determining if a number is prime or not without factoring the number, and it does so in polynomial time. Previously we only had algorithm that would output either: Not a prime (and you could be sure that the number wasn't a prime) or it...
- Carceri
- Post #11
- Aug 10, 2002
- Forum: Ask a Technical Professional
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Can the system datalinks be hardware encrypted?

RSA is an encryption algorithm, but is normally used to encrypt a small piece of random data to be used as a key for a faster conventional algorithm since RSA is extremely slow. You were probably thinking of the Diffie-Hellman key exchange protocol which is used only for exchanging keys. Given...
- Carceri
- Post #17
- Jul 28, 2002
- Forum: Ask a Technical Professional
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Can the system datalinks be hardware encrypted?

RC5 and 3DES are not related to the factoring of large numbers. Still your point is valid. I don't see algorithms like 3DES, Rijndael, Mars, Serpent, RC5, RC4, RC6, IDEA, CAST, etc... being broken in the near future (if ever). That was my point. Of cause you could look into the chip to read out...
- Carceri
- Post #12
- Jul 27, 2002
- Forum: Ask a Technical Professional
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Can the system datalinks be hardware encrypted?

Sure you could implement an encryption algorithm in hardware and integrate it into the CPU or any other chip that needed to communicate securely. The problem is that you need to store the key somewhere, and having to actually make the key a part of the chip would probably be very expensive since...
- Carceri
- Post #3
- Jul 26, 2002
- Forum: Ask a Technical Professional
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Quantum Computing...

It's funny what people call a one time pad. The one time pad is what was described earlier: Choose a completely random bitstring where each bit is choosen with probability 0.5 and independant of each other, then XOR that bitstring with the plaintext. It's easy to prove that this gives an...
- Carceri
- Post #10
- Jul 14, 2002
- Forum: Ask a Technical Professional
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Quantum Computing...

I have no idea where to start, but having taken courses in complexity theory, quantum computing, cryptography, cryptologic protocols and quantum information theory I guess I am expected to contribute to this thread. First the interesting topic of how fast a quantum computer is. The answer is...
- Carceri
- Post #8
- Jul 14, 2002
- Forum: Ask a Technical Professional
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Algorithm Complexity Analysis

Well, because binary representation is the only way to encode som instance of a problem on a computer the most accurate results are given by considering the length of the binary input string. A computer will work on the binary representation and the longer it is the more time it will take...
- Carceri
- Post #2
- Apr 24, 2002
- Forum: Ask a Technical Professional
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Non-determinism, Polynomial time problems and NP-complete

<< Actually it is unknown whether Quantum Polynomial is equivalent to non-deterministic polynomial time. Factoring and Discrete Log are in Quantum Polynomial time -- though neither are known (or believed to be) NP-hard problems. >> Ok, I was not being very specific. Here are some results from...
- Carceri
- Post #9
- Mar 22, 2002
- Forum: Ask a Technical Professional

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