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Top 10 incident response mistakes

Reading time9 min

Imagine someone withdrew money from a company's account at night. The next morning panic breaks out, leading to yet more problems. The IT department can reinstall a compromised system from scratch or restore it from backup. Reinstalling from scratch will wipe out all traces left by the attackers, and external investigators will have to search for clues in other systems. Restoring from backup carries the risk of accidentally reinstating a compromised image. In this paper, we will describe common mistakes that experts make when responding to security incidents.

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Information is changed by entropy

Reading time2 min

According to the no-cloning theorem it is impossible to create an independent and identical copy of an arbitrary unknown quantum state. We cannot delete any quantum information as well. All changes in time of the state vector in quantum mechanics are described by the action of unitary operators. Accordingly, there must be an operator performing a deleting operation. The operator must be a zero matrix in order to nullify quantum information totally in all cases. But a zero matrix is not a uninaty or hermitian matrix. Therefore there is no such unitary operator that can delete information.

   This might be proven in another way. Let us imagine the double-slit thought experiment where interference exists when we do not know about the system and interference does not when we know about the system. Assume we have a storage where the data is stored and the experiment is being conducted with knowing about the system. Suppose we destroy the storage. What does the screen in the experiment show us? Quantum mechanics tells us that there must not be interference. Should it appear after the data is destroyed? Since the wave function has collapsed it cannot be restored. If there is a chance to delete the information in the experiment, it means that the wave function must go back to the initial state and show us interference, which is a contradiction.

   Based on the foregoing, we will consider the quantum eraser experiment. In that experiment information is neither erased nor disappeared. It is being changed. That is the key point. We increase entropy. If there is a 50 per cent chance to get interference then the entropy = 1 (max value). The same with a spin. If we change spins of elementary particles, for example in the Stern–Gerlach experiment with different axes measurements, we do not delete the information about the states of particles, we increase the entropy. Changing does not equal deleting. 

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Total votes 3: ↑3 and ↓0+3

How to Restore Hard Disk Capacity and Recover Missing Space

Reading time18 min
If the disk space in your computer is incorrectly displayed, or free disk space decreases, or the overall disk performance deteriorates, all that may happen for a number of reasons. Read this article to find out how to restore original capacity of a hard disk and recover the missing disk space.

Total votes 5: ↑0 and ↓5-5

How to Recover Data From a Hikvision DVR

Reading time5 min
From this article, you will learn how to recover data from DVR and NVR video recorders. We will explore the peculiarities of how they store video files, why such files can be lost, and how they can be recovered. In the process, we’ll be using a IP network video recorder Hikvision DS-7104NI-Q1/4P.

Total votes 14: ↑3 and ↓11-8

Data Recovery from LVM Volumes in Linux

Reading time5 min
Would you like to know how to use the LVM technology in Linux? How to create an LVM volume, how to configure and mount it in your operating system, how to add and remove disks, and how to recover the information you have accidentally deleted? In today’s article, you will find all of that – and even more.

Total votes 15: ↑3 and ↓12-9

Active Restore: Can we Recover Faster? Much Faster?

Reading time5 min
Backing up valuable data is a proven practice, but what if we need to continue work immediately after a natural disaster or other disruptive events, and every minute is important? Our team at Acronis decided to see how quickly we can start an operating system. This is our first post from the Active Restore series. Today I will tell you how we launched our project with Innopolis University, which solutions were studied, and what we are working on today. All the details are under the Cut.

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Total votes 15: ↑14 and ↓1+13

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