How to read and write biometric data from/to a java card

[posey]

I want to read and write biometric data from/to a java card, and I am new to javacard platform.
Here are my questions:
- I just want to read and write biometric data from/to java card. Can I use some simple read/write methods to read and write biometric data from/to java card? Is it necessary to write an applet for this?

- If I created an applet for java card. How can I set the applet ID?

- I heard that Application Protocol Data Unit can help me do these, so how can I use it for my work?

These questions may be very basic, but I really don't know these. Can someone give me any help?
Thanks for any help

[ThePhoenyx]

An APDU (Application Protocol Data Unit) is actually the transport protocol (like tcp/ip) between the card and the computer. If you need to
do unusual things you would need to learn this, similar to needing to learn tcp/ip to talk low-level to a router.

When you create an applet you need to set an AID for the card. If you use Eclipse or the JCIDE from here, you set the AID while creating the
applet. Also when you transfer the applet to the card (depending on which program you use to do it) you have to give the AID as a parameter.
The AID can be made up by you if it is to be a local use card, or if creating them for sale you need to request an AID from (forgive me if I am
wrong) the IETF or IANA, I'm not sure who.

Biometric data is usually written to a data object on the card and then retrieved by the pc application to do the matching. There ARE cards
that can do it on-card but the applet/card can be quite expensive.

I hope this has helped you.

ThePhoenyx

[posey]

An APDU (Application Protocol Data Unit) is actually the transport protocol (like tcp/ip) between the card and the computer. If you need to
do unusual things you would need to learn this, similar to needing to learn tcp/ip to talk low-level to a router.

When you create an applet you need to set an AID for the card. If you use Eclipse or the JCIDE from here, you set the AID while creating the
applet. Also when you transfer the applet to the card (depending on which program you use to do it) you have to give the AID as a parameter.
The AID can be made up by you if it is to be a local use card, or if creating them for sale you need to request an AID from (forgive me if I am
wrong) the IETF or IANA, I'm not sure who.

Biometric data is usually written to a data object on the card and then retrieved by the pc application to do the matching. There ARE cards
that can do it on-card but the applet/card can be quite expensive.

I hope this has helped you.

ThePhoenyx

Hi ThePhoenyx. Thank you for your detailed reply! It's very helpful to me!
I still have a question. Where can I find the related doc or spec for the introduction and usage of Application Protocol Data Unit?