Content Extraction Signatures.

摘要: Motivated by emerging needs in online interactions, we define a new type of digital signature called 'Content Extraction Signature' (CES). A CES allows the owner, Bob, document signed Alice, to produce an 'extracted signature' on selected extracted portions original document, which can be verified (to originate from Alice) any third party Cathy, without knowledge unextracted (removed) portions. The therefore achieves verifiable content extraction with minimal multi-party interaction. We specify desirable functional and security requirements (including efficiency requirement: should more efficient either computation or communication than simple multiple solution). propose analyse four provably secure constructions satisfy our requirements, evaluate their performance characteristics.