I am currently studying a module on Security Technology at university and will share what I am learning and understanding on here, it may or may not interest you but it will also help me with revision for my courses. It may appear basic to begin with but that is because we are all beginners to the course and they are breaking us in gently :P
If you have a read you may find that you do infact enjoy what you are reading and could ask me questions about it and find that you may want to do something similar to myself as I find it a rather interesting subject.
BioMetrics litterally means the 'measure of life' which therefore means a way in which you can measure life, there are many different ways of doing this and it has been around for centuries - for example in the 14th century in China they stamped both palm and footprints onto paper in order to indentify people and used mainly to distinguish children.
In 1890 a man called Alponse Bertillon invented a way of keeping track of criminals by taking multiple body measurements, such as length of arm, skull etc. The problem was that Bertillonage was measured by many different people and with many different measuring tools, which made it near impossible to standardize the measurements in which would be taken and therefore result in lack of accuracy when the results when be taken from the same person again. It also had the issue that some people who attempted the technique would round up, whilst others would round down therefore could mean that the same person being measured by two different people could end up with completely different results, which therefore leads to mistaken indentity.
Sir Edward Henry - Edward Henry worked for the Bengal police and was eventually promoted to Commissioner at Scotland Yard after using the Bertillonage technique throughout his career, but then introducing the fingerprint taxonomy which was the identification of others by their finger prints.
There are also many other ways in which the biometrics of something can be recorded that arent neccesarily connected to human life, in order to roughly work out the age of a tree you can count the rings inside the tree and also with clams you can count the shell rings.
Use of Biometrics within technology
There are many many ways in which biometrics are used within everyday life such as your social security number, passports, medical records, dental records, drivers license, student ID, credit cards... you get the picture; These are all created and can be used for identification of a person.
The main reason for Biometrics in the modern day is for verification and security, verification defines if the person in question is actually who they say they are, this can be done via a password, PIN, signature etc. Whereas Identification is actually finding out who the person is I.E the forms you fill in whilst applying for passports and such.
It is infact rather easy to have your identification if it was just as simple as filling out a form, so therefore there are more accurate ways in which you can be identified and verified, such as a picture ID, but there are also more complicated ways which would be used in higher security situations, such as a bank vault... This ranges from fingerprints - in use with a scanner, Iris/Retina scanners which involve the use of infra-red lasers to read the patterns of the blood vessels within your eyes as they are unique to each of the people that use them because everyones blood vessel patterns are different to others.
Main methods of identification and verification are:
Hand Geometry - finger length/width
Iris Scan - Front of eye
Retina Scan - Back of eye
DNA - Blood, hair etc.
I should also mention that it is vital for all data that is being used for these processes is stored securely and to be encryted to maintain the high security level.