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Computer Security
Computer security is the prevention/detection of, and response to, any unauthorized actions by users of a computer system. Questions about security practices and principles belong here.
1,022 Questions
How is A VPN is able to provide secure communication?
At first vpn hides IP address and it changes IP address in a remote site. It gives the scope to surf anonymously on internet and access in a remote site. More details are in related links section.
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Answer Explanation: Only one key would be required for everyone to be able to encrypt and decrypt the message. Symmetric cryptography uses the same "shared secret" key for encrypting and decrypting a message. A message encrypted using a symmetric encryption algorithm can be decrypted by anyone with the key. For this reason it is very important to ensure that the key is protected from unauthorized use. One of the primary security issues surrounding the use of symmetric cryptography is the method used to transport the key to users who need it, as most forms of communication are susceptible to eavesdropping.
How do you decrypt a data file to that has been encrypted with the users public key?
When you reference a "public key" you are implying that the file has been encrypted using "asymmetric cryptography". In asymmetric cryptography, encryption and decryption depend on a key PAIR. The user retains their private key and publishes their public key. Anyone can encrypt a file using the user's public key and send it to them. The only person who should be able to decrypt a file encrypted with that public key is the holder of the private key - which, unless the user has made the mistake of sharing their private key - means that only the original user can decrypt the messages sent to them. Most of the asymmetric encryption algorithms use pretty much the same method to decrypt that was used to encrypt, but use the "other" key from the key pair. Messages encrypted using the private key can only be decrypted using the public key - which provides some authentication that the message indeed came from the holder of the private key. Messages encrypted using the public key can only be decrypted by the holder of the private key, so messages sent to them should be secure.
What is availability for IA security?
One of the basic themes of IA is that it is composed of three principles - which have the memorable acronym CIA. C = confidentiality: only those who should be able to see the data can see it. I = integrity: the data is only changed by those authorized to change it and is not being corrupted accidentally or intentionally. A = availability: users can access the data when they want to or need to.
Attacks against availability include denial of service (DoS) attacks which tie up resources and bog down networks to the point that legitimate users are not able to access them. Availability is also attacked by anything that causes the computer or the networks that provide access to it to crash. Availability is protected in IA through various methods including (but not limited to) redundancy, rerouting, disaster recovery plans, and contingency planning.
The method you are referring to is called SPI - Stateful Packet Inspection. A firewall employing SPI is commonly called a stateful firewall.
How do you keep confidential files secure?
The best way is to simply not save them. However, since that is impractical, you can hide folders if you have admin control of the account on the PC, password protect folders, and password protect individual files.
What is Integrity according to Computer Security?
In the context of computer security, "integrity" is the "I" in the "CIA" triad, i.e. Confidentiality, Integrity, and Availability. Integrity refers specifically to data being protected from unauthorized changes. The changes could be intentional, accidental, or simple corruption. Intentional changes could be things like an intruder trying to cover his tracks by modifying the log files to delete entries showing his activity or someone hacking into a a school database to change their grade in a class. Man-in-the-middle attacks can be attacks on integrity where a message is intercepted, modified, and then forwarded to the intended recipient. Accidental changes would be things like someone deleting data by executing the wrong command. An example of corruption would be a software flaw that allows overwriting database files when someone inserts a string that is longer than intended in a data field and the input is not validated before the write is executed.
What the security of public key asymetric cryptography is based upon?
The security of asymmetric cryptography depends on the difficulty - of determining the private key given the public key. For example: an asymmetric encryption algorithm might rely on the difficulty of factoring a very large number into two prime factors. If the cost of computational power and time to perform the factoring exceeds the value of the encrypted information, then the encryption would be considered sufficiently secure for practical purposes. An asymmetric encryption algorithm may also rely on the difficulty of computing discrete logarithms. Both the "factoring products of primes" and "calculating discrete logarithms" approaches to recovering the "private" key of an asymmetric encryption are assumed to rely on the difficulty of brute force attacks. Sometimes algorithms are improperly implemented, the keys are too short, or an inherent weakness is found that allows faster recovery of the key by restricting the key space that must be searched. In these cases, the security of the asymmetric encryption may be significantly less than would be otherwise assumed - i.e. it may be possible to break the encryption fast enough to make it worth the effort.
What is able to identify users with public key infrastructure?
I'm not certain of the intent of the question but it sounds like what is being asked is how you can know the actual identity of someone from their public key - i.e. how you can know that the public key really belongs to the person it purports to belong to. PKI (public key infrastructure) is one way to establish with reasonable certainty that a key really belongs to the entity that is claimed. PKI uses a system of Certificate Authorities (CA) and Registration Authorities (RA). At the top of the chain is the Registration Authority that everyone trusts. Users register their public keys with the RA. CA's also register their certificates withe the RA along with proof that they are who they say they are. CA's are repositories of public keys that the public can access. They sign the keys with their own certificates vouching for the identity of the public key owner. The identity of the CA may, in turn, be vouched for by an RA or higher CA who sign the certificate of that particular CA.
What causes attenuation on wireless signals?
Attenuation limits the range of radio signals. Wireless signals are radio waves. Like any type of electromagnetic radiation, they are subject to attenuation. Attenuation normally includes propagation losses caused by the natural expansion of the radio wave front in free space (which usually takes the shape of an ever-increasing sphere), absorption losses (sometimes called penetration losses), when the signal passes through media not transparent to electromagnetic waves, diffraction losses when part of the radio wavefront is obstructed by an opaque obstacle, and losses caused by other phenomena.
Propagation losses become worse as the distance between the source and receiver increases. Just like a light source becomes less intense to the observer as they move away from the light, the radio signal becomes more faint as the receiver becomes more distant from the signal source. Distance is thus an attenuating factor for all wireless signals.
Absorption losses occur when some of the signal is absorbed by the media between the radio signal source and the receiver. All types of electromagnetic radiation is subject to this kind of attenuation as well: sunlight is attenuated by dark glasses, X-rays are attenuated by lead, and light is attenuated while passing through seawater. For radio waves on earth (where wireless computer signals are important), the primary "medium" air and attenuation is an exponential function of the path length through the air. Attenuation is also affected by all the materials a signal must travel through including not only air, but building materials (e.g. wood, concrete, steel, glass, etc.) if the wireless connection is made within a building and weather when the wireless signal is traveling outside the building (e.g. rain, sleet, snow, fog, smog, smoke, etc.). Each medium soaks up different amounts of radio energy. Metals tend to be the worst. It is possible to build what is known as a Faraday Cage that will shield radio signals almost completely by absorbing them and conducting their energy away to "ground".
Some materials block radio signals almost completely even if they are not grounded. Even if they block them, they may still reflect some of the radio waves off in another direction causing interference or simply lengthening the effective path the waves must travel between the source and receiver. If the radio-opaque material has gaps in it, some of the signal may still leak through, but less than the amount that ran into the barrier. A simple analogy would be a screen that lets most of the light through but blocks some of it, lessening the intensity of the light that does make it through. Another analogy would be polarized sunglasses that only pass the light that is vibrating in the direction of the polarization.
A Virtual Private Network is a method of sending business information from one place to another in a secure manner. The level of security is strong enough for international financial transactions.
What is hardening a computer system?
In essence - hardening a computer system means removing or shutting down everything on it that is not required for the intended operation and further configuring it to protect those connections and services that ARE required.
In more detail, "Hardening" a computer system refers to configuring the settings to protect it from threats. It includes things like turning on and configuring the host based firewall, encrypting the password file, setting network comminications to use encryption and authentication, blocking remote administration except through controlled channels. The purpose of system hardening is to eliminate as many security risks as possible. This typically includes removing all non-essential software programs and utilities from the computer. While these programs may offer useful features to the user, if they provide "back-door" access to the system, they must be removed during system hardening. The BIOS may be configured to prevent booting from anything but the local hard drive once the OS is installed and then secured with a password to prevent changes. Alternatively, the CD drive is listed as the first boot device, which enables the computer to start from a CD or DVD if needed. File and print sharing are turned off if not absolutely necessary and TCP/IP is often the only protocol installed. The guest account is disabled, the administrator account is renamed, and secure passwords are created for all user logins. Auditing is enabled to monitor unauthorized access attempts. The system may also be configured not to respond to "ping" requests. There are many other configuration settings that can be utilized to further secure the system.
Does an account user know when someone access their account?
That depends entirely on whether the system administrator has enabled the features of the OS that cause it to display past logins to the user. If they enable the feature, then it may show the user the most recent attempted and successful logins, from which the user can identify if someone else has been accessing their account. As an example: If you see that the last login was 12 hours ago and you haven't logged in for 2 days, you know something is up.
What are the disadvantages of using the same password for all networks?
I can think of two disadvantages right off:
1) The biggest one is that if someone compromises the password on one network it is compromised on ALL the networks. Hackers will often exploit this by attacking a less secure network to harvest passwords and then try them on more secure networks that the users also use
2) The other disadvantage is that if you forget the password you have now locked yourself out of all the networks. Somehow I don't see this as very likely though.
What are the impact of e-commerce in the business environment?
Compared with traditional commerce, e-commerce is a fundamentally different way of doing business. It is 24/7; global; anonymous; hugely competitive with quality, price and delivery easy to compare; it is cheaper to operate because telecoms is cheaper than transportation; it is very transparent with more info, less selling and more telling; payment is faster; it is more flexible and responsive for changes to offerings such as price and specification; business is place independent; methods of selling can be changed relatively easily.
TELNET
i think its supposed to be: Xkx.exe
and i think its a program for computers.
The computer program only runs on Windows 32 bit and is mentioned in the same sentence as spyware - if in doubt, chuck it out.
What is CA Pest Patrol Realtime Protection?
it comes bundled with Comcast constant guard. It is used for the Comcast toolbar for anti-virus protection. If you are running an anti-virus suite I would delete it because it uses a lot of cpu and also it will interfere with your security suite and slow your pc down. P.S. if you cannot delete it use REVO uninstaller! then go to 1] C:drive 2]Program 86 files 3]common files 4]scanner file and delete that ca pest file
How do you get a coworker fired anonymously if they are trying to get you fired?
Do something bad, blame it on them and tell your boss they did it!
