partialIv

This header parameter holds a part of the IV value. When using the COSE_Encrypt0 structure, a portion of the IV can be part of the context associated with the key (Context IV), while a portion can be changed with each message (Partial IV). This field is used to carry a value that causes the IV to be changed for each message. The Partial IV can be placed in the unprotected bucket, as modifying the value will cause the decryption to yield plaintext that is readily detectable as garbled. The "Initialization Vector" and "Partial Initialization Vector" header parameters MUST NOT both be present in the same security layer.