Deferred Media Key Delivery in IP Multimedia Subsystem
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current methods for secure transmission of deferred media information in IP Multimedia Subsystem (IMS) face issues such as excessive storage requirements for the Key Management Server (KMS) and key expiration problems, particularly in the Otway Rees protocol, which complicates the secure delivery of media information when the receiving party is offline.
Innovation Solution
A method where the sending party encrypts key generation parameters with a shared key (Ka) and sends them to the receiving party's mailbox server, which then forwards them to the KMS, allowing the KMS to generate and manage media keys without storing them, reducing interaction and storage burdens, and ensuring secure decryption upon the receiving party's online status.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the KMS stores generated media keys for deferred media information transmission, then the receiving party can obtain the media key when online, but the storage requirements and complexity of the KMS increase excessively
Solution Approach 1:
The patent extracts the media key storage function from the KMS by having the sending party generate and encrypt the media key locally using the receiving party's public key. The encrypted media key is then stored in the mailbox server instead of the KMS, eliminating the need for the KMS to store media keys while ensuring reliable delivery when the receiving party comes online.
Solution Approach 2:
The patent uses public key cryptography to create an encrypted copy of the media key that can be stored and transmitted independently. The sending party generates a media key, encrypts it with the receiving party's public key, and stores the encrypted version in the mailbox server. This allows the KMS to focus on authentication while the encrypted media key is copied and stored elsewhere for later retrieval.
2Reliability
If the Otway Rees protocol is used for media security, then authentication is achieved, but the KMS must store shared keys which causes statefulness problems and excessive storage
Solution Approach 1:
The patent implements self-service by having the sending party autonomously generate the media key and encrypt it with the receiving party's public key. This eliminates the need for the KMS to maintain shared keys or track authentication states, as the encryption capability is self-contained in the receiving party's public key stored in the mailbox server.
Solution Approach 2:
The patent uses disposable public keys stored in the mailbox server that can be used indefinitely without requiring the KMS to maintain state. Each receiving party has a public key that can be used to encrypt media keys for any number of deferred transmissions, eliminating the need for the KMS to store or manage ongoing key relationships.
3Reliability
If ticket-based system is used for deferred media information, then secure transmission is achieved, but the interaction between sending party and KMS becomes excessive
Solution Approach 1:
The patent applies preliminary action by having the receiving party pre-generate and store their public key in the mailbox server before any media transmission occurs. When deferred media information needs to be sent, the sending party can immediately encrypt the media key with the pre-stored public key without needing to interact with the KMS, significantly reducing signaling interactions while maintaining secure transmission.
Data Source
AI summary
The present invention discloses a method for transmitting deferred media information in the IP Multimedia Subsystem: the sending party of the media information sends key generation parameters encrypted with s Ka to the mailbox server of the receiving party of the media information; the mailbox server saves the encrypted key generation parameters, and sends the encrypted key generation parameters to a Key Management Server (KMS); the KMS generates a media key K, and forwards the K to the sending party through the mailbox server of the receiving party; the receiving party obtains the encrypted key generation parameters from the mailbox server, and sends to the KMS; the KMS generates the K and sends the K to the receiving party; the receiving party decrypt the encrypted media information by using the K. The present invention also discloses a corresponding system. The present invention decreases the signaling interaction between the sending party and the KMS, reduces the storage pressure of the KMS, and realizes the secure transmission of the deferred media in the IMS.