The Security of ChaCha20-Poly1305 in the Multi-user Setting

ePrint Report: The Security of ChaCha20-Poly1305 in the Multi-user Setting

Jean Paul Degabriele, Jérôme Govinden, Felix Günther, Kenneth G. Paterson

The ChaCha20-Poly1305 AEAD scheme is being increasingly widely deployed in practice. Practitioners need proven security bounds in order to set data limits and rekeying intervals for the scheme. But the formal security analysis of ChaCha20-Poly1305 currently lags behind that of AES-GCM. The only extant analysis (Procter, 2014) contains a flaw and is only for the single-user setting. We rectify this …

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