Our Online Store have the new products: RFID antenna board. Currently it can work with JC10M24R and JCOP4 card chips.
Compared with normal cards, the antenna board module has a smaller size and fixed holes, which is easy to integrate in the IOT(Internet Of Things) project.

3DES Key

Algorithm School

Moderator: UNKNwYSHSA

sakkiotto
Posts: 12
Joined: Thu Dec 03, 2015 5:29 am
Points :86
Contact:

3DES Key

Post by sakkiotto » Wed Jan 18, 2017 11:58 pm

I have to encrypt data with 3DES algo in my applet. I also need to decrypt the data in my host application. And the key for 3DES should be 24 bytes, anyone can figure out how to extend the 16 byte key to 24 byte key?

Here is my code

Code: Select all

cipherDES = Cipher.getInstance(Cipher.ALG_DES_CBC_ISO9797_M1, false);
randomData = RandomData.getInstance(RandomData.ALG_SECURE_RANDOM);

sessionKey = (DESKey) KeyBuilder.buildKey(KeyBuilder.TYPE_DES,KeyBuilder.LENGTH_DES3_2KEY, false);
randomData.generateData(sessionKeyBytes, (short) 0, (short) 15);sessionKey.setKey(sessionKeyBytes, (short) 0);
cipherDES.init(sessionKey, Cipher.MODE_ENCRYPT);

JCaberham
Posts: 26
Joined: Mon Nov 30, 2015 3:02 am
Points :208
Contact:

Re: 3DES Key

Post by JCaberham » Thu Jan 19, 2017 10:36 pm

If you use bouncy castle, you can use a 16 byte 2TDEA key.

User avatar
marjkbadboy
Posts: 33
Joined: Fri Jul 31, 2015 2:47 am
Points :217
Contact:

Re: 3DES Key

Post by marjkbadboy » Thu Jan 19, 2017 10:40 pm

Usually, the structure of 24 byte key is ABA, where
A: the first 8 bytes of 16 byte key;
B: the next 8 bytes of 16 byte key.
It's hunting season!

Post Reply Previous topicNext topic

Who is online

Users browsing this forum: No registered users and 22 guests

JavaCard OS : Disclaimer