transientMap in node.js and getTransient in chaincode

Question

Can somebody explain the usage of transientMap in channel.sendTransactionProposal(request, timeout) and getTransient() in chaincode with an usecase. What is so special with data of getTransient() when compared to normal arguments

Answer 1

Regular arguments are part of the endorsement proposal and therefore persisted, while transient map is not. Therefore if you would like to pass some data which you do not want to be kept in endorsement proposal you can use GetTransient API. For example if you are doing application level encryption you can pass keys and crypto material within transient map.