AES Is Great … But We Need A Fall-back: Meet ChaCha and Poly1305

TLS_ECDHE_RSA_WITH_CHACHA20_POLY1305_SHA256   = {0xCC, 0xA8}
TLS_ECDHE_ECDSA_WITH_CHACHA20_POLY1305_SHA256 = {0xCC, 0xA9}
TLS_DHE_RSA_WITH_CHACHA20_POLY1305_SHA256 = {0xCC, 0xAA}
TLS_PSK_WITH_CHACHA20_POLY1305_SHA256 = {0xCC, 0xAB}
TLS_ECDHE_PSK_WITH_CHACHA20_POLY1305_SHA256 = {0xCC, 0xAC}
TLS_DHE_PSK_WITH_CHACHA20_POLY1305_SHA256 = {0xCC, 0xAD}
TLS_RSA_PSK_WITH_CHACHA20_POLY1305_SHA256 = {0xCC, 0xAE}

Implementation

X is created with K, c and n
y ← X
for i ← 0 to 9 do
/* Column Round */
(x0, x4, x8, x12) ← QR(x0, x4, x8, x12)
(x5, x9, x13, x1) ← QR(x5, x9, x13, x1)
(x10, x14, x2, x6) ← QR(x10, x14, x2, x6)
(x15, x3, x7, x11) ← QR(x15, x3, x7, x11)
/* Diagonal Round */
(x0, x5, x10, x15) ← QR(x0, x5, x10, x15)
(x1, x6, x11, x12) ← QR(x1, x6, x11, x12)
(x2, x7, x8, x13) ← QR(x2, x7, x8, x13)
(x3, x4, x9, x14) ← QR(x3, x4, x9, x14)
end for
Z ← X + y

Conclusions

ASecuritySite: When Bob Met Alice

This publication brings together interesting articles related to cyber security.

Prof Bill Buchanan OBE

Written by

Prof at Napier. Serial innovator. Crypto Punk. Believer in fairness, justice & freedom. EU Citizen. Auld Reekie native. Old World Breaker. New World Creator.

ASecuritySite: When Bob Met Alice

This publication brings together interesting articles related to cyber security.