Asymmetric Loss-Tolerant Authentication

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Last updated 2020-01-09 (latest revision 2019-07-08)
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Establishing authenticity of a stream of datagrams in the presence of multiple receivers is naively achieved through the use of per-packet asymmetric digital signatures, but at high computational cost for both senders and receivers. Timed Efficient Stream Loss-Tolerant Authentication (TESLA) instead employs relatively cheap symmetric authentication, achieving asymmetry via time-delayed key disclosure, while adding latency to verification and imposing requirements on time synchronization between receivers and the sender to prevent forgery. This document introduces Asymmetric Loss-Tolerant Authentication (ALTA), which employs an acyclic graph of message authentication codes (MACs) transmitted alongside data payloads, with redundancy to enable authentication of all received payloads in the presence of certain patterns of loss, along with regularly paced digital signatures. ALTA requires no time synchronization and enables authentication of payloads as soon as sufficient authentication material has been received.


Kyle Rose (

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