IT Applications Theory Slideshows

By Mark Kellymark@vceit.comVceit.com

Virtual TeamFile Management

Managing & Transmitting files

• Encryption• Access hierarchy• Backups• Virus scanners• Classifying and naming files• Directory/folder/site structures• Version control

Managing FilesUse a file manager like Windows Explorer.

Preferably a better file manager.

File:

•Opening•Copying•Moving•Renaming•Deleting•Categorising•Viewing•Archiving

etc

A better file manager – File Commander

And other tools

There are many utilities which help manage particular types of files, or carry out specialised actions…

Managing Picture Files

Picture:

•Previews•Resizing•Reformat•Sort•Create webpage•Contact sheet•File Info

Mass File Renaming

Instantly renames thousands of files with great flexibility. Saves HOURS of labour when working with large numbers of files.

Thumbnailed web photo galleries

Converts any number of photos into pages full of small thumbnailed images linked to the large pictures.

Find where disk space is used/wasted

Searching for filesFind files matching given criteria (e.g. name, file type, contents)

anywhere on a computer or network.

Search & Replace over many filesSome text editors let you carry out a search and replace over many files at once. Far easier than making the same edit on 1200 files individually!

Transmitting Files

• Files can be sent using the normal web HTTP protocol but it’s not the best way.

• File Transfer Protocol (FTP) is the standard way of transferring files over the internet – especially big files and large numbers of files.

• FTP client is like a 2-pane file manager with your local files in one pane and the remote files on the webserver in the other pane.

Filezilla – an open source FTP client

Commercial file-sharing services

Commercial file-sharing services

Email attachments

• Easy to send• Limited by size of recipient’s mailbox or ISP

restrictions

Don’t recommend

• Snail mail• Couriers

We need ICT solutions!

Data Security

• Virtual teams often work with confidential or secret data

• All data needs to be protected against loss or damage

• Sensitive information needs protection against theft

Passwords

• Passwords can be applied to:– Individual computers– Network access– Website access– FTP access– Opening documents– Changing documents

A password-protected database

Biometric ID• Passwords are weak protection• Easily forgotten, discovered, guessed• Biometric ID measures a unique physical

attribute of an individual, e.g.– Fingerprint– Iris pattern (the coloured bit of the eye)– Retinal pattern (the blood vessels at the back of

the eye)

• Can’t be copied, faked, stolen as passwords and swipe cards can

Encryption

• Makes information unreadable for unauthorised people

• Public Key encryption does not have an unlocking key - the weak point of all previous encryption systems

• Public key encryption (look up RSA, PGP, SSL) is very, VERY hard to break

• Even if an encrypted document is stolen or copied, it is worthless to the thief

Encryption• SSL (Secure Socket Layer) encrypts web traffic• Is active when the padlock in your browser

snaps shut• Messages between web servers (e.g. banks)

and visitors are encrypted by the sender and decrypted by the recipient

• Secure sites sometimes identifiable by a HTTPS:// prefix

Access hierarchy• Different users get different levels of access to

data• Level of access based on what they need to

get their work done• Prevents unskilled, stupid or

evil people deliberately, carelessly or accidentally destroying data

Safe Disposal• ‘Deleted’ files are easily recovered• To be safe, unwanted files should be wiped• Military-grade wiping involves overwriting data at

least 7 times with rubbish data• Computers being disposed of should have their

hard disks reformatted.• But reformatting can be reversed!• Some organisers shred used hard disks to be sure.

The disks are physically pulverised.

Hard disk destruction

http://www.youtube.com/watch?v=8qImGK8bHjEhttp://www.youtube.com/watch?v=sQYPCPB1g3o

Hours of crushing fun…

Access hierarchy• Databases, for example, can assign rights such

as:– See some data, but not all– See all data, but not add/delete/change change it– Add data but not delete any– Add and delete data but not change any

programming or presentation layouts– Access all areas

Access Privileges in Filemaker

Backups

• Backup = copying data so it can be restored if the original is lost or damaged

• Must be done regularly (daily!)• Must be stored offsite• Procedure must be tested

and documented

Backup types

• Full = copy absolutely everything: new and old data and programs

• Incremental (partial, differential) = copy only files that are new or have been changed since the last full backup.

Typical Scheme

• Weekly full backups• Daily incremental backups• To restore data, reload the latest full backup

and then add on all the incremental backups made since then.

• Look up “grandfather-father-son” scheme, a variety of “rotation backup”

Backup Media

• “Media” = what the data is saved to• Tape = large capacity, slow, wears out,

expensive. Very common• Removable hard disk = fast, large capacity,

cheap.• CD/DVD = relatively low capacity, easily

damaged. Non-magnetic, so not hurt by electromagnetic fields as are tapes, HDDs.

Backup Media

• Selection criteria:–Read/write speed–Capacity–Lifetime of recorded data–Durability of media

Archiving

• Copy obsolete data to secondary storage (e.g. DVD) and delete the original data.

• Backing up = copy data, keep the original.

Virus scanners

• Must have up-to-date virus definitions• Must be running all the time• Must be accurate:

– false-positives – wrongly believes a virus exists – false-negatives – fails to identify a virus

• Even market-leading products are imperfect• Some free products (e.g. Avira) outperformed

Symantec & McAfee in a test in 2009.

Other scanners

• Malware – spyware, adware. Either does bad things (e.g. monitoring users’ actions) or is badly programmed and badly affects the stability of computers.

Other scannersTrojan Horses – bad software installed by users

who think it’s innocent. Payloads:– Keylogger: records passwords, credit card info,

bank account logins & sends them to hackers.– Spamming agent: your computer acts as a zombie

sending spam on behalf of the hacker– Distributed Denial Of Service (DDOS)

attack: your computer is taken over and joins a concerted attack on a server chosen by the hacker.

Firewalls• Closes unused internet communication ports• Your computer has 65535 of them, but you

only use about 3.• Hackers can gain entry to a PC through

unguarded ports• Firewalls close the unused ports• Open ports are watched to ensure only

authorised programs use them (preventing Trojans sending spam or DDOS attacks)

Software Firewalls• Can be software or hardware firewalls• Software: Windows Firewall, Zone Alarm• Needs training when first installed. You teach

it which programs are allowed to connect to the internet

Hardware firewalls• Routers – on all Local Area Networks, and in

nearly all home/office cable/ADSL modems• Can use Stateful Packet Inspection (SPI) to

examine inside data packets to see if they’re harmful.

• Protect against incoming bad data, but not outgoing bad data. If you’re already infected by a Trojan, a router won’t stop your PC sending spam, keylogs etc

PLEASE NOTE

• A firewall (hardware or software) will not stop viruses!

• A firewall will not stop viruses!

• A firewall will not stop viruses!

• A firewall will not stop viruses!• A firewall will NOT stop viruses!• I’m glad we got that clear

Classifying and naming files• Random file naming leads to confusion, time

wasting and difficulty finding information• Store all documents in one location, not

sprinkled around the computer and network!• Other team members might need to access

your documents, so they need to be able to find them simply by filename.

• With thousands of files, a ramshackle pile of careless filenames will become unmanageable.

File naming

• All team members must use the same sort of software – preferably the same version (e.g. MS Word 2007)

Filenaming• Use a regular pattern in your filenames• E.g. all invoices begin with INV- with customer

surname+initials-date-your initials– INV-smithjs-20081228-KEL.xls

• Note the date code above: year (2008) month (12) day (28) so they sort nicely

• All team members must agree to and cooperate with the file naming scheme

Directory/folder/site structures

• Logical directory structure and naming is vital on networks and web/FTP servers

• Should be hierarchical. E.g. website for team on the corporate site…– corporate.com (organisation’s site)– Corporate.com/vt (virtual team’s directory)– Corporate.com/vt/calendars (all calendars stored here)– Corporate.com/vt/calendars/fred.cal (fred’s calendar)

Directory/folder/site structures

• Where would the team store minutes of their meetings?– Corporate.com/vt/minutes– Corporate.com/vt/minutes/2009– Corporate.com/vt/minutes/2009/hardware_team– Corporate.com/vt/minutes/2009/hardware_team/minutes_20091231.htm

Valid alternative…– Corporate.com/vt/minutes– Corporate.com/vt/minutes/hardware_team– Corporate.com/vt/minutes/hardware_team/2009– Corporate.com/vt/minutes/hardware_team/2009/minutes_20091231.htm

•Both are organised and hierarchical•Different organisation of team/year importance.•Decision may depend on whether they will need to search more by team or date. •Naming schemes should complement the way the team will work.

TIP: Avoid the temptation to abbreviate too much: e.g. a path likeCorporate.com/vt/min/hw/09/m091231.htm

could easily become unintelligible.

Version control

• Keeps tracks of documents as they are being developed

• Avoids confusion about which is the latest version

• Simple to achieve…

Version Control

• Never re-save a document with the same name

• Can never recover the overwritten version• First save as document-v1.doc• Edit it, save as document-v2.doc• Re-edit. Save as document-v3.doc

Software Versioning

• E.g FredSoft 7.1.2• Major version: 7• Minor version: 1• Subversion: 2

Version Control

• Easy to keep track of which is newest• Especially if you have copies on your PC,

network, home PC, website and smartphone!• Also, can revert to a previous version if you

discover you’ve ruined the document.• All team members must comply with the

versioning scheme.• Can delete old versions when all is finished.

Version Control System

• Automates version numbering of team documents

• Keeps track of when documents are copied, edited, saved etc

• Major software often has inbuilt versioning features (e.g. Word, wiki software)

Version control

• See TRACK CHANGES in MS Word.• Tracks all changes made to a document.• Can undo changes made by someone else.

By Mark Kellymark@vceit.comvceit.com

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