errors , threats Flashcards
arithmetic issues
rounding,truncating,overflow,fixed no. of bits
data transmission errors
data doesn’t reach destination intact - data corruption by
atmospheric conditions (cable heat too much,moisture- unable to carry data)
distance limits (attenuation)
interference +causing devices (motors, fluorescent lighting, cables running by electric cables)
programming errors
bugs- can lead to catastrophic failure of system
data verification
systematic process for evaluating performance + compliance of data set when compared to standards in project documentation to ascertain its completeness, correctness + consistency
RFID
radio frequency identification
makes use of radio signals to transfer data from tag attached to an object
tag contain identification data sensed by receiving device
uses electromagnetic fields to automatically identify and track tags attached to objects.
sql injection + fix
gives access to hackers - reveals all data in table
use GUI components to restrict data, remove INSERT, UPDATE, + DELETE rights to any website
validate user input to check for possible sql injections
fix hardware failure
RAID 1 (mirroring) + RAID 5 (striping) to provide one or more hard drives in case of hard drive failure
if there is complete failure, the backup could be used to recover a prev version of the data
psu
power supply unit
converts alternating current to direct current
trojan horse
seemingly harmless program that when activated causes harm to computer system
spyware
capture info like web browsing, e-mails, usernames + passwords, credit card info
can transmit data to another persons computer over internet
pharming
attack intended to redirect websites traffic to another bogus site by changing host file on victims computer or by exploitation of vulnerability in DNS server software
ransomware
prevents user from accessing their computer until ransom is paid
DoS attacks
denial of services attacks
attempts to make server/network resource unavailable to users
DDosS attacks
distributed denial of service attack that uses more than one computer distributed worldwide to put heavy burden on service
infected w malicious program that makes server go wrong
harder to withstand than DoS attacks
open ports
can be exploited through code vulnerabilities or malware
botnets
aka zombie army
several internet computers set up to forward transmissions (including spam + viruses) to other computers on internet w/o knowledge of owners
computer is infected + controlled by author remotely on net - serve in botnet
zombie created by internet port that has been left open - small trojan program installed for future activation
wifi vulnerabilities
to encrypt wifi- pre Shared key or certificate must be proved by client
open networks don’t use encryption – all data traffic visible to malicious actor, who wants to see any online communication of people nearby. When insecure apps/sites accessed on an unencrypted connection, data becomes a risk of data leak: unauthorised/unintentional transfer of sensitive information from mobile device to Internet service
Captive portal, pages – open guest networks will display captive Portal page, asking for personal information to access Wi-Fi connection. Look like standard web page so people hand over info placing their info at risk
RAID
redundant array of inexpensive disks
protection against hard drive failure
- improves performance + provides protection of data
uses 2 or more hard disks so if 1 fails, other will contain copy
RAID 1
protection of data creates
duplicate of other disk-mirroring- won’t improve performance but offers data protection
data stored on 2 hard disks simultaneously- but only accessed from 1 (second is backup)
RAID 0
performance based- no data protection-if one disk crashes , data lost
RAID 5
RAID 5 is an improved version of RAID 0 and offers both data protection and improved performance .It requires a minimum of 3 disks and utilises parity and striping
In RAID 5, the data is written in stripes across 3 hard drives and utilises an extra 8 bytes of data as parity that will kick in if one disk fails.
Disk striping with RAID provides data redundancy and reliability. Parity data is commonly calculated by using the binary exclusive function stored on a physical drive in the RAID set. If a storage drive in the striped RAID set fails, the data is recoverable from the remaining drives and the parity stripe.