 
Summary: Linear Time Erasure Codes With Nearly Optimal Recovery
(Extended Abstract)
Noga Alon
Jeff Edmonds
Michael Luby
Abstract
An (n, c, , r)erasure code consists of an encoding
algorithm and a decoding algorithm with the following
properties. The encoding algorithm produces a set of
bit packets of total length cn from an nbit message.
The decoding algorithm is able to recover the message
from any set of packets whose total length is r, i.e.,
from any set of r/ packets. We describe erasure codes
where both the encoding and decoding algorithms run
in linear time and where r is only slightly larger than
n.
1 Introduction
Most existing and proposed networks are packet
based, where a packet is fixed length indivisible unit of
information that either arrives intact upon transmis
