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<?xml-stylesheet type="text/xsl" href="https://community.arm.com/utility/feedstylesheets/rss.xsl" media="screen"?><rss version="2.0" xmlns:dc="http://purl.org/dc/elements/1.1/" xmlns:slash="http://purl.org/rss/1.0/modules/slash/" xmlns:wfw="http://wellformedweb.org/CommentAPI/"><channel><title>custom encryption and decryption</title><link>https://community.arm.com/developer/tools-software/tools/f/keil-forum/29623/custom-encryption-and-decryption</link><description> 
ho dudes. 

 
i wanna make some custom encryption functions to stop people
snooping at my data. i dont wanna use aes or the other ones. 

 
btw, i think that i may need the encryption template, when i saw
through some crypto code. 

 
can someone help</description><dc:language>en-US</dc:language><generator>Telligent Community 10</generator><item><title>RE: custom encryption and decryption</title><link>https://community.arm.com/thread/128027?ContentTypeID=1</link><pubDate>Thu, 21 Feb 2013 23:39:52 GMT</pubDate><guid isPermaLink="false">dd9e70c8-6d3c-4c71-b136-2456382a7b5c:5b32d527-c76d-4a91-a2e6-480e55eedffc</guid><dc:creator>Santosh G</dc:creator><description>&lt;p&gt;&lt;p&gt;
I really dont think its right forum to post this question but
since you have worked extensively in this domain your inputs would be
of great help.&lt;/p&gt;

&lt;p&gt;
Requirement: Avoiding repeated decryption of file/data&lt;br /&gt;
Expected behavior of Algorithm:&lt;/p&gt;

&lt;p&gt;
Example: consider file(f0) on encryption gives encrypted file(ef0)
and key(ek0) i.e&lt;br /&gt;
f0 ----&amp;gt; ef0 and ek0.(repeating encryption of encrypted data)&lt;br /&gt;
ef0 ----&amp;gt; ef1 and ek1.&lt;br /&gt;
ef1 ----&amp;gt; ef2 and ek2.&lt;br /&gt;
. .&lt;br /&gt;
. efn-1 ----&amp;gt; efn and ekn.&lt;/p&gt;

&lt;p&gt;
On applying decryption on efn using ekn I should be able to get f0
bypassing decryption of (efn-1, ...ef2, ef1). Hence key is expected
to have delta value during each successive encryption.&lt;/p&gt;

&lt;p&gt;
Is there any encryption and decryption algorithm currently
displaying this behavior?&lt;/p&gt;

&lt;p&gt;
Looking forward for your suggestion.&lt;/p&gt;
&lt;/p&gt;&lt;div style="clear:both;"&gt;&lt;/div&gt;</description></item><item><title>RE: custom encryption and decryption</title><link>https://community.arm.com/thread/128016?ContentTypeID=1</link><pubDate>Tue, 19 Feb 2013 18:57:16 GMT</pubDate><guid isPermaLink="false">dd9e70c8-6d3c-4c71-b136-2456382a7b5c:2b7caa6d-f3f3-44ea-87c1-c43fa8325976</guid><dc:creator>John Linq</dc:creator><description>&lt;p&gt;&lt;p&gt;
=&amp;gt; And what if the Chinese knows about this back door without
NSA knowing about it...&lt;/p&gt;

&lt;p&gt;

=====================================================================================&lt;/p&gt;

&lt;p&gt;
August 17, 2005&lt;br /&gt;
Chinese Cryptographers Denied U.S. Visas&lt;/p&gt;

&lt;p&gt;
&lt;a href="http://www.schneier.com/blog/archives/2005/08/chinese_cryptog.html"&gt;www.schneier.com/.../chinese_cryptog.html&lt;/a&gt;&lt;/p&gt;

&lt;p&gt;
=&amp;gt;&lt;/p&gt;

&lt;p&gt;
Chinese cryptographer Xiaoyun Wang, the woman who broke SHA-1 last
year, was unable to attend the Crypto conference to present her paper
on Monday. The U.S. government didn&amp;#39;t give her a visa in time:&lt;/p&gt;

&lt;ul&gt;
  &lt;li&gt;
  On Monday, she was scheduled to explain her discovery in a
  keynote address to an international group of researchers meeting in
  California.
  &lt;/li&gt;

  &lt;li&gt;
  But a stand-in had to take her place, because she was not able
  to enter the country. Indeed, only one of nine Chinese researchers
  who sought to enter the country for the conference received a visa
  in time to attend.
  &lt;/li&gt;
&lt;/ul&gt;

&lt;p&gt;
Sadly, this is now common:&lt;/p&gt;

&lt;ul&gt;
  &lt;li&gt;
  Although none of the scientists were officially denied visas by
  the United States Consulate, officials at the State Department and
  National Academy of Sciences said this week that the situation was
  not uncommon.
  &lt;/li&gt;

  &lt;li&gt;
  Lengthy delays in issuing visas are now routine, they said,
  particularly for those involved in sensitive scientific and
  technical fields.
  &lt;/li&gt;
&lt;/ul&gt;
&lt;/p&gt;&lt;div style="clear:both;"&gt;&lt;/div&gt;</description></item><item><title>RE: custom encryption and decryption</title><link>https://community.arm.com/thread/117185?ContentTypeID=1</link><pubDate>Tue, 19 Feb 2013 08:04:59 GMT</pubDate><guid isPermaLink="false">dd9e70c8-6d3c-4c71-b136-2456382a7b5c:986f391b-3a6f-4fc2-b404-95ff957ae856</guid><dc:creator>Dan Curran</dc:creator><description>&lt;p&gt;&lt;p&gt;
&lt;a href="http://en.wikipedia.org/wiki/Blowfish_"&gt;en.wikipedia.org/.../Blowfish_&lt;/a&gt;(cipher)&lt;/p&gt;

&lt;p&gt;
I helped implement this in an earler project - seemed easy enough
to do and was secure enough for what I needed ( settop box)&lt;/p&gt;
&lt;/p&gt;&lt;div style="clear:both;"&gt;&lt;/div&gt;</description></item><item><title>RE: custom encryption and decryption</title><link>https://community.arm.com/thread/136961?ContentTypeID=1</link><pubDate>Thu, 14 Feb 2013 02:58:47 GMT</pubDate><guid isPermaLink="false">dd9e70c8-6d3c-4c71-b136-2456382a7b5c:e707a2db-3664-480b-ad61-91e4d9a802b1</guid><dc:creator>ImPer Westermark</dc:creator><description>&lt;p&gt;&lt;p&gt;
And what if the Chinese knows about this back door without NSA
knowing about it...&lt;/p&gt;
&lt;/p&gt;&lt;div style="clear:both;"&gt;&lt;/div&gt;</description></item><item><title>RE: custom encryption and decryption</title><link>https://community.arm.com/thread/128017?ContentTypeID=1</link><pubDate>Thu, 14 Feb 2013 02:28:06 GMT</pubDate><guid isPermaLink="false">dd9e70c8-6d3c-4c71-b136-2456382a7b5c:707390a0-db6f-4f43-9e05-0b1eb89da177</guid><dc:creator>Mike Kleshov</dc:creator><description>&lt;p&gt;&lt;p&gt;
&lt;i&gt;&amp;quot;AES has been adopted by the U.S. government and is now used
worldwide&amp;quot;&lt;/i&gt;&lt;/p&gt;

&lt;p&gt;
It makes you think, doesn&amp;#39;t it? What if the NSA left a backdoor in
this cipher?&lt;/p&gt;
&lt;/p&gt;&lt;div style="clear:both;"&gt;&lt;/div&gt;</description></item><item><title>RE: custom encryption and decryption</title><link>https://community.arm.com/thread/106870?ContentTypeID=1</link><pubDate>Thu, 14 Feb 2013 02:26:05 GMT</pubDate><guid isPermaLink="false">dd9e70c8-6d3c-4c71-b136-2456382a7b5c:e0e6c06c-5a30-4b8e-a667-668107c89a9b</guid><dc:creator>ImPer Westermark</dc:creator><description>&lt;p&gt;&lt;p&gt;
The established algorithms are established because people have
looked at the code and not seen any insecurities. They are secure
because of the access to the keys not the accesss to the code.&lt;/p&gt;

&lt;p&gt;
Encryption cracking is normally done using statistical methods.
Write your own code and make it complex. Have statistical methods
unroll it within seconds or minutes. Just because your complexities
aren&amp;#39;t good enough.&lt;/p&gt;

&lt;p&gt;
An encryption algorithm have very much in common with a good
random number generator (RNG). It needs to permute the data in ways
that removes the correlations you have between characters in the
original data from the encrypted data. So you can&amp;#39;t see patterns in
the output even when you know that there are lots of spaces and lots
of dual-characters in the input data.&lt;/p&gt;

&lt;p&gt;
Sorry, but you better invest 10-20 years with pure math and
statistics before you decide to work on crypto algorithms. And the
10-20 years better be in the correct areas of math and statistics,
picking up the latest knowledge about different methods to analyze
data.&lt;/p&gt;
&lt;/p&gt;&lt;div style="clear:both;"&gt;&lt;/div&gt;</description></item><item><title>RE: custom encryption and decryption</title><link>https://community.arm.com/thread/119972?ContentTypeID=1</link><pubDate>Thu, 14 Feb 2013 02:22:24 GMT</pubDate><guid isPermaLink="false">dd9e70c8-6d3c-4c71-b136-2456382a7b5c:44477ca1-05ed-44c9-96dc-0497c62dd94a</guid><dc:creator>Tamiryan Michael</dc:creator><description>&lt;p&gt;&lt;p&gt;
&amp;quot;everybody knows the ones like aes and knows how to reverse
them&amp;quot;&lt;/p&gt;

&lt;p&gt;
Aha.&lt;/p&gt;

&lt;p&gt;
&amp;quot;AES has been adopted by the U.S. government and is now used
worldwide. It supersedes the Data Encryption Standard (DES),[5] which
was published in 1977. The algorithm described by AES is a
symmetric-key algorithm, meaning the same key is used for both
encrypting and decrypting the data.&amp;quot;&lt;/p&gt;

&lt;p&gt;
Hmm.&lt;/p&gt;
&lt;/p&gt;&lt;div style="clear:both;"&gt;&lt;/div&gt;</description></item><item><title>RE: custom encryption and decryption</title><link>https://community.arm.com/thread/106869?ContentTypeID=1</link><pubDate>Thu, 14 Feb 2013 02:20:48 GMT</pubDate><guid isPermaLink="false">dd9e70c8-6d3c-4c71-b136-2456382a7b5c:4bb908f5-1b16-49fb-9228-4f63d394a19b</guid><dc:creator>Mike Kleshov</dc:creator><description>&lt;p&gt;&lt;p&gt;
&lt;i&gt;if i have my own they wont know how to reverse and my data is
protected more.&lt;/i&gt;&lt;/p&gt;

&lt;p&gt;
The problem is that if you get the code here, it won&amp;#39;t be your
own.&lt;/p&gt;
&lt;/p&gt;&lt;div style="clear:both;"&gt;&lt;/div&gt;</description></item><item><title>RE: custom encryption and decryption</title><link>https://community.arm.com/thread/106866?ContentTypeID=1</link><pubDate>Thu, 14 Feb 2013 02:19:25 GMT</pubDate><guid isPermaLink="false">dd9e70c8-6d3c-4c71-b136-2456382a7b5c:200b958e-da13-407c-b6e1-ae72b31b846a</guid><dc:creator>Tamiryan Michael</dc:creator><description>&lt;p&gt;&lt;p&gt;
&amp;quot;everybody knows the ones like aes and knows how to reverse
them&amp;quot;&lt;/p&gt;

&lt;p&gt;
Ohm really?!&lt;br /&gt;
Hmm.&lt;br /&gt;
Encryption is not for the common man. Use a well establish, open
method and READ why is it safe. Ho, and stop using this sms language.
that&amp;#39;s a start.&lt;/p&gt;
&lt;/p&gt;&lt;div style="clear:both;"&gt;&lt;/div&gt;</description></item><item><title>RE: custom encryption and decryption</title><link>https://community.arm.com/thread/80985?ContentTypeID=1</link><pubDate>Thu, 14 Feb 2013 02:07:42 GMT</pubDate><guid isPermaLink="false">dd9e70c8-6d3c-4c71-b136-2456382a7b5c:3502e549-3c5d-4d04-a9e5-1c0ff554794b</guid><dc:creator>marrom makash</dc:creator><description>&lt;p&gt;&lt;p&gt;
yo per westmerk.&lt;/p&gt;

&lt;p&gt;
everybody knows the ones like aes and knows how to reverse them.
if i have my own they wont know how to reverse and my data is
protected more.&lt;/p&gt;
&lt;/p&gt;&lt;div style="clear:both;"&gt;&lt;/div&gt;</description></item><item><title>RE: custom encryption and decryption</title><link>https://community.arm.com/thread/68097?ContentTypeID=1</link><pubDate>Thu, 14 Feb 2013 02:02:48 GMT</pubDate><guid isPermaLink="false">dd9e70c8-6d3c-4c71-b136-2456382a7b5c:3f90c50b-652c-428c-a648-24701da21e98</guid><dc:creator>ImPer Westermark</dc:creator><description>&lt;p&gt;&lt;p&gt;
There are lots of good code. But for some reason you have already
refused to use it when you decided that you don&amp;#39;t want to use &amp;quot;aes or
the other ones&amp;quot;.&lt;/p&gt;

&lt;p&gt;
So why don&amp;#39;t you like to use one of the established crypto
algorithms?&lt;/p&gt;
&lt;/p&gt;&lt;div style="clear:both;"&gt;&lt;/div&gt;</description></item></channel></rss>