paper 1 - laws and protocols Flashcards
what is a protocol?
a set of rules for how devices communicate and how data is transmitted across a network
what information do protocols cover?
how communication between two devices should start and end, how the data should be organised, and what the devices should do if data goes missing
what are the three components of a data packet?
- header - contains control information - like the envelope of a letter - includes packet’s destination address (where it’s going), the source address (where it’s come from) and the packet number
- payload - the letter inside the envelope - the thing the person is likely to read, and the reason it was sent in the first place. might be part of an email, document, web page of streamed video.
- likely to include a checksum number - a form of validation used to check that the payload data hasn’t been corrupted during transit. the sending and receiving devices both calculate a checksum value by performing a function on the payload data. if the values match then the data has been received correctlly
what does the TCP/IP protocol do?
dictate how data is sent between networks
what two protocols is the TCP/IP protocol made up of?
Transmission control protocol (TCP) and Internet Protocol (IP)
what does the transmission control protocol (TCP) do?
set the rules for how devices connect on the network. It’s in charge of splitting the data into packets and reassembling the packets back into the original data once they reach the receiving device. It’s also responsible for checking the data is correctly sent and delivered
what is the internet protocol (IP) responsible for?
packet switching
what is the Hyper Text Transfer Protocol (HTTP) used for?
used by web browsers to access websites and communicate with web servers
what is the HTTPS protocol?
a more secure version of HTTP. encrypts all information sent and received
what is the file transfer protocol (FTP) used for?
used to access, edit and move files between devices on a network e.g. to access the files on a server from a client computer
what does POP3 stand for?
Post Office Protocol - version 3
what is POP3 used for?
used to retrieve emails from a server. The server holds the email until you download it at which point it is deleted from the server
what does IMAP stand for?
Internet Message Access Protocol
what is IMAP used for?
used to retrieve emails from a server. The server holds the email until you delete it - you only download a copy. Used by most web-based email clients
what does SMTP stand for?
simple mail transfer protocol
what is SMTP used for?
used to send emails. Also used to transfer emails between servers
what is a layer?
a group of protocols which have similar functions
what is the name of layer 4?
application layer
what does layer 4 do?
turns data into websites and other applications and vice versa
what is the name of layer 3?
transport layer
what does layer 3 do?
controls data flow - e.g. splitting data into packets and checking packets are correctly sent and delivered
what is layer 2 called?
network layer
what does layer 2 do?
makes connections between networks, directs data packets and handles traffic. used by routers
what is layer 1 called?
data link layer
what does layer 1 do?
Passes data over the physical network. Responsible for how bits are sent as electrical signals over cables, wireless and other hardware
what protocols work in layer 4 (the application layer)?
HTTP, FTP, SMTP
which protocols work in layer 3 (the transport layer)
TCP (transmission control protocol)
what protocols work in layer 2 (the network layer)?
IP
what protocols work in layer 1 (the data link layer)?
ethernet
what are the advantages of using layers?
- it breaks network communication into manageable pieces. This helps developers to concentrate on only one area of the network without having to worry about others
- as layers are self-contained, they can be changed without the other layers being affected
- having set rules for each layer forces companies to make compatible, universal hardware and software, so different brands will work with each other and in basically the same way
what is the first principle of the data protection act?
data must only be used in a fair and lawful way
what is the second principle of the data protection act?
data must only be used for the specified purpose
what is the third principle of the data protection act?
data should be adequate, relevant and not excessive for the specified use
what is the fourth principle of the data protection act?
data must be accurate and kept up-to-date
what is the fifth principle of the data protection act?
data should not be kept longer than necessary
what is the sixth principle of the data protection act?
the rights of the data subject must be observed
what is the seventh principle of the data protection act?
data should be kept safe and secure
what is the eighth principle of the data protection act?
data should not be transferred abroad without adequate protection
what does the data protection act 1998 do?
it gives rights to data subjects
what is a data subject?
a person whose personal data is stored on computer systems
what does the data protection act mean for organisations?
- before collecting personal data an organisation must register with the government, saying what data they’ll collect and how they’ll use it
- the act gives data subjects the right to see the personal data an organisation holds about them
- there are some exceptions to this, e.g. organisations don’t have to disclose the data they hold if it could affect national security, tax assessment, or the outcome of a court case
- if a data subject feels an organisations use of their data has caused them distress, they may be entitled to compensation
what does the Freedom of Information Act 2000 allow?
public access to data - it allows members of the public to access information held by a public organisation about that organisation’s activities. The Act covers information stored in computer data files (including audio and video files), emails, and printed documents
what are some exceptions to the Freedom of Information Act 2000?
an organisation can withhold requested information if it is intended for future publication, or if disclosing it could affect national security or cause people harm
what does the computer misuse act 1990 prevent?
illegal access to files - it was introduced to stop hacking and cyber crime
what three new offences did the Computer Misuse Act 1990 introduce?
- Gaining unauthorised access to a private network or device, e.g. through hacking
- gaining unauthorised access to a network or device in order to commit a crime like stealing data or destroying the network
- unauthorised modification of computer material - e.g. deleting or changing files. The Act also makes it illegal to make, supply or obtain malware
what does the Copyright, Designs and Patents Act 1988 protect?
innovation - it was introduced to protect intellectual property - anything that someone has created
what does the Copyright, Designs and Patents Act 1988 make illegal?
it makes it illegal to share copyrighted files without the copyright holder’s permission, use unlicensed software of plagiarise somebody else’s work. Copyright holders can make money by granting permission to use the material for a fee
why has the internet made it harder to protect copyrighted content?
because of the ease of file sharing. It’s also difficult to enforce copyright if content is held on servers in countries with more relaxed copyright laws
what do Creative Commons licenses allow?
legal file sharing - they allow you to legally share media and software online without having to ask for permission first. Intellectual property owners use creative commons licences when they want other people to share of build upon their work
what are the four main types of creative commons license?
- Attribution - work can be shared, copied or modified, but the copyright holder has to be credited
- Share-alike - modified works can only be distributed with the same license terms as the original
- Non-commercial - nobody can use the copyrighted work for profit
- No derivative works - the work can be copied and distributed, but can’t be modified or built upon
can you combine CC licences?
yes
what does it mean for works to be in the public domain?
they don’t have any copyright attached to them, meaning you can copy them and share them as you wish.
when does UK copyright expire?
70 years after the creators death, at which point their creation enters the public domain - Shakespeare’s plays, Beethoven’s symphonies and da Vinci’s paintings are all now in the public domain
