user41513: We may certainly say that a "permissioned" blockchain cannot have a native coin (or cryptocurreny) since in permissioned blockchain we need a permission to be eligible to participate for transactions validation and so having a native coin in a permissioned blockchain is not meaningful. 
However, on the other hand, can we say that having a native coin/cryptocurrency for a "permissionless" blockchain is crucial? Or is there any permissionless blockchain without native coin? In that case, how to ensure security and how to motivate miners/validators for participation in transactions validation? 

user92114: Ripple is actually a permissioned "chain", even if we stretch what the definition of a chain is. It is run by validators and as far as I know, it is not permissionless (which I equate with "trustless"). 
I do not see a specific need for a permissionless network to have its own coin or token. It could in theory still be driven on top of an already-existing coin from another network. It depends alot on your proof-of-what algorithm. You could have a network that awards "miners" ETH for doing "work" even if your own network does not have its own native token, per se.

41513: <p>We may certainly say that a <strong>"permissioned"</strong> blockchain <strong>cannot</strong> have a <strong>native coin</strong> (or cryptocurreny) since in <strong>permissioned</strong> blockchain we need a permission to be eligible to participate for transactions validation and so having a native coin in a permissioned blockchain is not meaningful. </p>

<p>However, on the other hand, can we say that having a <strong>native coin/cryptocurrency</strong> for a <strong>"permissionless"</strong> blockchain is <strong>crucial</strong>? Or is there any <strong>permissionless</strong> blockchain <strong>without native coin</strong>? In that case, how to ensure security and how to motivate miners/validators for participation in transactions validation? </p>
 92114: <p>Ripple is actually a permissioned "chain", even if we stretch what the definition of a chain is. It is run by validators and as far as I know, it is not permissionless (which I equate with "trustless"). </p>

<p>I do not see a specific need for a permissionless network to have its own coin or token. It could in theory still be driven on top of an already-existing coin from another network. It depends alot on your proof-of-what algorithm. You could have a network that awards "miners" ETH for doing "work" even if your own network does not have its own native token, per se.</p>
