There is an extremely low probability of additional

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Unformatted text preview: e with CRC code must be used to insure that residual errors are detected and the frame flagged. There is an extremely low probability of additional undetected errors that may escape this scrutiny. These errors may affect the encryption process in unpredictable ways, possibly affecting the decryption stage and producing data loss, but will not compromise the security of the data. B1.2 SECURITY CONCERNS Security concerns in the areas of data privacy, authentication, access control, availability of resources, and auditing are to be addressed in higher layers and are not related to this Recommended Standard. The coding layer does not affect the proper functioning of methods used to achieve such protection at higher layers, except for undetected errors, as explained above. The physical integrity of data bits is protected from channel errors by the coding systems specified in this Recommended Standard. In case of congestion or disruption of the link, the coding layer provides methods for frame re-synchronization. B1.3 POTENTIAL THREATS AND ATTACK SCENARIOS An eavesdropper can receive and decode the codewords, but will not be able to get to the user data if proper encryption is performed at a higher layer. An interferer could affect the performance of the decoder by congesting it with unwanted data, but such data would be rejected by the authentication process. Such interference or jamming must be dealt with at the Physical Layer and through proper spectrum regulatory entities. CCSDS 131.0-B-2 Page B-1 August 2011 CCSDS RECOMMENDED STANDARD FOR TM SYNCHRONIZATION AND CHANNEL CODING B1.4 CONSEQUENCES OF NOT APPLYING SECURITY There are no specific security measures prescribed for the coding layer. Therefore consequences of not applying security are only imputable to the lack of proper security measures in other layers. Residual undetected errors may produce additional data loss when the link carries encrypted data. B2 SANA CONSIDERATIONS The recommendations of this document do not require any action from SANA. B3 B3.1 PATENT CONSIDERATIONS TURBO CODING Implementers should be aware that a wide class of Turbo codes is covered by a patent by France Télécom and Tél...
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This document was uploaded on 03/06/2014.

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