RISE AB RISE AB Object Security for Constrained RESTful Environments (OSCORE) uses AEAD algorithms to ensure confidentiality and integrity of exchanged messages. Due to known issues allowing forgery attacks against AEAD algorithms, limits should be followed on the number of times a specific key is used for encryption or decryption. This document defines how two OSCORE peers must follow these limits and what steps they must take to preserve the security of their communications. Therefore, this document updates RFC8613. Furthermore, this document specifies Key Update for OSCORE (KUDOS), a lightweight procedure that two peers can use to update their keying material and establish a new OSCORE Security Context.