Description
v1.06 is an editorial improvement of v1.05, with important modifications to SHA1DK. The two new protection-key methods are still proposed to replace the current default and alternatives, with the explicitly-named ODF 1.2 alternatives identified as deprecated and not to be produced in ODF 1.3 documents.
AUTHZ160 does not depend on a hashing algorithm to match is value in order to authenticate removal of a protection.
SHA1DK is password based but it uses salt values and iterated hashing to make it far more costly to attempt to discover the password used by repeated trials. Passwords that are used should still be considered compromisable simply because the protection key, even though 320 bits, is still available in plain sight and subject to off-line attacks.
1. Rationale
1.1 Vulnerability of Password Hash Values
1.2 SHA1DK for Password-Based Protection-Key Values
1.3 AUTHZ160 for Password-Less Protection-Key Values
2. Proposed Changes
3. Deployment Considerations
3.1 Down-Level Considerations
3.2 Immediate Usabilty of AUTHZ160 for Default Protection
Keys
3.3 Confirmation of Resilient Down-Level Treatment
3.4 Future-Proofing of Extended ODF 1.2 Consumers and
Producers
[Note: In section 2, the separation of the iteration count from the cryptographically-random salt portion is made explicit. It is now possible to produce the count as the result of iterative hashing under a time constraint.]
