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Security Profiles: AMS, CFDP. Scott Burleigh NASA JPL 13 June 2006. AMS Security – General. Requirements Authentication of service providers and consumers Control of service access, at message subject granularity Message integrity and confidentiality Mechanisms
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Security Profiles: AMS, CFDP Scott Burleigh NASA JPL 13 June 2006
AMS Security – General • Requirements • Authentication of service providers and consumers • Control of service access, at message subject granularity • Message integrity and confidentiality • Mechanisms • Asymmetric encryption of authenticators • Symmetric encryption of message content • Pre-placed keys and access control lists (MIB) • No dynamic key distribution or ACL update mechanism identified yet.
AMS Security – Overview (1) • MAMS message header authenticator: • 4-byte “hood” (four randomly selected ASCII characters) in clear text. • Concatenation of hood plus a well-known message-type-specific name, encrypted in the private key of the sender. • Receiver of MAMS message decrypts the encrypted part of the authenticator using the public key of the sender, verifies it. • MIB at each node contains all relevant asymmetric keys.
AMS Security – Overview (2) • MIB contains, for each message subject: • List of authorized senders. • List of authorized receivers. • Symmetric key for encryption/decryption of messages on this subject.
CFDP Security – General • Currently, none at all. • Tentative requirements: • Mutual authentication of CFDP entities • Metadata integrity and confidentiality • File data integrity and confidentiality • Proposed mechanisms • Optional inclusion of authenticator in Metadata PDU • Asymmetric encryption of Metadata • Symmetric encryption of file data • Pre-placed keys (MIB)
CFDP Security – General (2) • An alternate proposal: • Implement security at the PDU level rather than the file level. • A better fit for users that want to make immediate use of partially received data, i.e., individual PDUs. Unaffected by loss of Metadata PDU. • Add per-segment metadata (an LV) to each file data segment PDU: • Brief authenticator, as for AMS. • Pre-placed keys in MIB, one per known CFDP entity: • Asymmetric keys for encryption/decryption of authenticator • Symmetric key for encryption/decryption of segment data