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RE: Editorial: Use of MAY in draft-ietf-ipsec-ikev2-algorithms
>I thought also that RC4 was not a restartable(seekable?) stream cipher and
>thus cannot tolerate lost or out of order packets unless special steps were
>taken (re-gen the key schedule for each packet?).
All stream ciphers use a key to produce a key stream. WEP needs a
different key stream for each packet, as would IPsec ESP if one tried to
use RC4 in this context. WEP achieved this by constructing a per-packet
key. An IV was simply concatenated with the rest of the key. This is how
the first three bytes of the packet key are "published."