» 
Arabic Bulgarian Chinese Croatian Czech Danish Dutch English Estonian Finnish French German Greek Hebrew Hindi Hungarian Icelandic Indonesian Italian Japanese Korean Latvian Lithuanian Malagasy Norwegian Persian Polish Portuguese Romanian Russian Serbian Slovak Slovenian Spanish Swedish Thai Turkish Vietnamese
Arabic Bulgarian Chinese Croatian Czech Danish Dutch English Estonian Finnish French German Greek Hebrew Hindi Hungarian Icelandic Indonesian Italian Japanese Korean Latvian Lithuanian Malagasy Norwegian Persian Polish Portuguese Romanian Russian Serbian Slovak Slovenian Spanish Swedish Thai Turkish Vietnamese

definition - OCB_mode

definition of Wikipedia

   Advertizing ▼

Wikipedia

OCB mode

                   

OCB mode (Offset Codebook Mode) is a mode of operation for cryptographic block ciphers.[1][2]

Contents

  Encryption and authentication

It was designed to provide both authentication and privacy. It is essentially a scheme for integrating a Message Authentication Code (MAC) into the operation of a block cipher. In this way, OCB mode avoids the need to use two systems; a MAC for authentication and encryption for privacy. This results in lower computational cost compared to the application of separate encryption and authentication functions.

OCB mode was designed by Phillip Rogaway, who credits Mihir Bellare, John Black, and Ted Krovetz with assistance and comments on the designs. It is based on the authenticated encryption mode IAPM due to Charanjit S. Jutla (see the OCB FAQ for more details).

There are three versions of OCB: OCB1, OCB2 and OCB3. OCB1 was published in 2001. OCB2 improves on OCB1 by allowing associated data to be included with the message — that is, data that are not encrypted but should be authenticated — and a new method for generating a sequence of offsets. OCB2 was first published in 2003, originally named AEM (Authenticated-Encryption Mode, or Advanced Encryption Mode). OCB3, published in 2011, changes again the way offsets are computed and introduces minor performance improvements.

OCB mode is listed as an optional method in the IEEE 802.11 wireless security standard as an alternative to CCM. OCB2 is standardized in ISO/IEC 19772:2009.[3]

  Performance

OCB performance overhead is minimal comparing to classical, non-authenticating modes like CBC. OCB requires one block cipher operation per each block of encrypted and authenticated message and one block cipher operation per each block of additional associated data. There are also two extra encryptions required at the end of process.

For comparison, CCM mode offering similar functionality requires twice as many block cipher operations per each message block (associated data requires one as in OCB).

  Patents

Two U.S. patents have been issued for OCB mode.[4] However, a special exemption has been granted so that OCB mode can be used in software licensed under the GNU General Public License without cost, as well as for any non-commercial, non-governmental application. Since the authors have only applied for patent protection in the U.S., the algorithm is free to use in software not developed and not sold inside the U.S.[5]

  See also

  References

  External links

   
               

 

All translations of OCB_mode


sensagent's content

  • definitions
  • synonyms
  • antonyms
  • encyclopedia

Dictionary and translator for handheld

⇨ New : sensagent is now available on your handheld

   Advertising ▼

sensagent's office

Shortkey or widget. Free.

Windows Shortkey: sensagent. Free.

Vista Widget : sensagent. Free.

Webmaster Solution

Alexandria

A windows (pop-into) of information (full-content of Sensagent) triggered by double-clicking any word on your webpage. Give contextual explanation and translation from your sites !

Try here  or   get the code

SensagentBox

With a SensagentBox, visitors to your site can access reliable information on over 5 million pages provided by Sensagent.com. Choose the design that fits your site.

Business solution

Improve your site content

Add new content to your site from Sensagent by XML.

Crawl products or adds

Get XML access to reach the best products.

Index images and define metadata

Get XML access to fix the meaning of your metadata.


Please, email us to describe your idea.

WordGame

The English word games are:
○   Anagrams
○   Wildcard, crossword
○   Lettris
○   Boggle.

Lettris

Lettris is a curious tetris-clone game where all the bricks have the same square shape but different content. Each square carries a letter. To make squares disappear and save space for other squares you have to assemble English words (left, right, up, down) from the falling squares.

boggle

Boggle gives you 3 minutes to find as many words (3 letters or more) as you can in a grid of 16 letters. You can also try the grid of 16 letters. Letters must be adjacent and longer words score better. See if you can get into the grid Hall of Fame !

English dictionary
Main references

Most English definitions are provided by WordNet .
English thesaurus is mainly derived from The Integral Dictionary (TID).
English Encyclopedia is licensed by Wikipedia (GNU).

Copyrights

The wordgames anagrams, crossword, Lettris and Boggle are provided by Memodata.
The web service Alexandria is granted from Memodata for the Ebay search.
The SensagentBox are offered by sensAgent.

Translation

Change the target language to find translations.
Tips: browse the semantic fields (see From ideas to words) in two languages to learn more.

last searches on the dictionary :

3271 online visitors

computed in 0.031s

   Advertising ▼

I would like to report:
section :
a spelling or a grammatical mistake
an offensive content(racist, pornographic, injurious, etc.)
a copyright violation
an error
a missing statement
other
please precise:

Advertize

Partnership

Company informations

My account

login

registration

   Advertising ▼