Sealing or binding is a concept in confidential computing that refers to the process of securely protecting and encrypting data within a trusted execution environment (TEE) or secure enclave. It allows sensitive data to be securely bound to the enclave's identity or state, ensuring its confidentiality and integrity.
Here's an overview of how sealing or binding works in confidential computing:
Data Encryption
Before sealing or binding, the sensitive data is typically encrypted using encryption keys that are generated and managed within the TEE or secure enclave. This encryption ensures the data remains confidential and protected even if the enclave's state is compromised.
Sealing Process
The sealing process involves associating the encrypted data with the enclave's identity or state. This linkage ensures that the sealed data can only be accessed or decrypted within the same or compatible enclave with the same identity or state.
Enclave Identity or State
The sealing process may bind the sealed data to specific attributes of the enclave, such as its measurement, cryptographic identity, or other security properties. This ensures that the data can only be accessed within an enclave that matches the specified attributes.
Key Management
The sealing process often involves the management of encryption keys used for sealing and unsealing data. These keys are securely stored within the enclave, safeguarded against unauthorized access or extraction.
Unsealing Process
When the enclave needs to access the sealed data, it goes through an unsealing process. This process verifies the enclave's identity or state compatibility with the sealed data and decrypts the data using the appropriate encryption keys.
Sealing or binding in confidential computing provides a mechanism to protect sensitive data and ensure its confidentiality and integrity within secure enclaves. It prevents unauthorized access or tampering of the data, even if the enclave's state is compromised. By associating the data with the enclave's identity or state, sealing enables secure storage, transmission, and processing of sensitive information in confidential computing environments.