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.

DES encryption with data length 132 byte

Algorithm School

Moderator: UNKNwYSHSA

RexLi
Posts: 9
Joined: Wed Dec 21, 2016 11:46 pm
Points :82
Contact:

DES encryption with data length 132 byte

Post by RexLi » Thu Mar 09, 2017 11:27 pm

I have to use DES alg in my applet. But the length of Data are 132 bytes. So I wonder if it's feasible to implement DES encryption with data length 132 byte?

Code: Select all

skey = (DESKey) KeyBuilder.buildKey(KeyBuilder.TYPE_DES,KeyBuilder.LENGTH_DES3_2KEY, false);
cDES = Cipher.getInstance(Cipher.ALG_DES_CBC_ISO9797_M2, false);
     
cDES.init(skey, Cipher.MODE_ENCRYPT);
cDES.doFinal(Data, doffset, dlen, EBuffer, eoffset); // Data and EBuffer are 132 byte length


User avatar
mabel
Posts: 237
Joined: Mon May 18, 2015 3:09 am
Points :1705
Contact:

Re: DES encryption with data length 132 byte

Post by mabel » Fri Mar 10, 2017 6:21 am

DES requires the data to be block-aligned to an 8 byte boundary. You can have different length input as long as the cipher instance pads the data. Then the output would be block-aligned.

Neqikoo
Posts: 7
Joined: Thu Feb 25, 2016 3:48 am
Points :74
Contact:

Re: DES encryption with data length 132 byte

Post by Neqikoo » Fri Mar 10, 2017 8:46 am

Under javacard implementation, the padding is done transparently so it can be block-aligned automatically. You don't need to worry about data length.

Post Reply Previous topicNext topic

Who is online

Users browsing this forum: No registered users and 19 guests

JavaCard OS : Disclaimer