- From: Joseph Reagle <reagle@w3.org>
- Date: Mon, 27 Aug 2001 15:39:29 -0400
- To: XML Encryption WG <xml-encryption@w3.org>
- Cc: Donald Eastlake 3rd <dee3@torque.pothole.com>
(Should the nonce be base64Binary? Also, I'm sure my text could benefit from suggestions. Is it in remote CipherReference values too? Donald, if you need to tweak given the changes to DigestMethod (is nonce before or after?) please do so.) http://www.w3.org/Encryption/2001/Minutes/010820-tele.html >Action Reagle: make it a declaration within CipherData using >Eastlake's nonce proposal text where necessary. --> http://www.w3.org/Encryption/2001/Drafts/xmlenc-core/Overview.html#sec-CipherData 3.2 The CipherData Element The optional Nonce attribute specifies the presence and length of a nonce value that is prepended to the CipherValue or data identified by the CipherReference. A nonce is a value (used only once) that is combined with the plaintext being encrypted in order to increase its entropy; this prevents "dictionary attacks" that encrypt "some known plaintext phrase with all possible keys so that the key for any given encrypted message containing that phrase may be obtained by lookup." [RFC2828]. Given the redundancy of XML, and the fact that attackers may know the data's structure applications are RECOMMENDED to encrypt data that is varied, either by its own nature or by use of the Nonce attribute. ... <attribute name="Nonce" type="base64Binary" use="optional"/> ...
Received on Monday, 27 August 2001 15:39:33 UTC