NFD » NDN Specifications

Packet Format v0.3 defines SignatureValue to be a signature over Name+MetaInfo+Content+SignatureInfo. For example, with SignatureType=3, it is ECDSA over SHA256{Name, MetaInfo, Content, SignatureInfo}. This definition makes it impossible to introduce new elements covered by signature in a compatible way.

To restore the design intention of SignatureValue, the definition shall be updated as follows:

• All elements before SignantureValue are covered by signature.
• All elements after SignatureValue are not covered by signature.

This enables future protocol versions to introduce new signed elements by adding them before SignatureValue or introduce new unsigned elements by adding them after SignatureValue.