dbms_obfuscation_toolkit...preventing double encryption...

From: alincoln <alincoln_at_edgewater.com>
Date: 28 Oct 2003 07:54:54 -0800
Message-ID: <3c5e17cb.0310280754.12e2fd1f@posting.google.com>

Hi all,

We are using the dbms_obfuscation_toolkit.DESEncrypt() and DESDecrypt() to process credit card data throughout our database...We are trying to setup some database functions to handle the encrypt/decrypt. What we would like to incorporate into the functions is a preventive mechanism that stops data from being encrypted a second/third/or more times...

For example...given two home-grown database function encrypt() and decrypt() we run the following commands...

<snip>

create table kris (col1 varchar2(90));

insert into kris values ('A');
insert into kris values ('AAAAAAAA');
insert into kris values ('4141414141414141');
insert into kris values ('515151515151');

commit;

prompt Original values...
select * from kris;

prompt **********************************************************

prompt Update encrypt() step one...
update kris set col1 = encrypt(col1, 'KEY1'); select * from kris;
select decrypt(col1, 'KEY1') from kris;

prompt **********************************************************

prompt Update encrypt() step two...
update kris set col1 = encrypt(col1, 'KEY1'); select * from kris;
select decrypt(col1, 'KEY1') from kris;

prompt **********************************************************

</snip>

Problem is, in step two, the data gets encrypted twice...Anyone know of anyway to detect and prevent double/triple/or-more encryption of data?

tia,

adym lincoln
alincoln_at_edgewater.com Received on Tue Oct 28 2003 - 09:54:54 CST