  Recent years have witnessed a slew of coding techniques custom designed for
networked storage systems. Network coding inspired regenerating codes are the
most prolifically studied among these new age storage centric codes. A lot of
effort has been invested in understanding the fundamental achievable trade-offs
of storage and bandwidth usage to maintain redundancy in presence of different
models of failures, showcasing the efficacy of regenerating codes with respect
to traditional erasure coding techniques. For practical usability in open and
adversarial environments, as is typical in peer-to-peer systems, we need
however not only resilience against erasures, but also from (adversarial)
errors. In this paper, we study the resilience of generalized regenerating
codes (supporting multi-repairs, using collaboration among newcomers) in the
presence of two classes of Byzantine nodes, relatively benign selfish
(non-cooperating) nodes, as well as under more active, malicious polluting
nodes. We give upper bounds on the resilience capacity of regenerating codes,
and show that the advantages of collaborative repair can turn to be detrimental
in the presence of Byzantine nodes. We further exhibit that system mechanisms
can be combined with regenerating codes to mitigate the effect of rogue nodes.
