It totally depends on the type of token / coin you are mining - basically the consensus on which the token in deployed.
If the coin is on PoW - proof of work - then yes, you will need energy-using equipment. (Mind my words - "using"). Only the latest ASIC miners are very energy intensive and they are only used for Bitcoin and for some tokens that are forks of the bitcoin code.
On the other hand PoS - Proof of Stake - is not energy intensive at all. There is definitely a need for nodes in this as well. However, they do not need to be as resource heavy as PoW tokens.
Security is determined by the consensus mechanism and how the transactions are being validated. For PoW - the more the nodes, the more secure is the blockchain - making it energy intensive.
PoS on the other hand requires more stakers on a node to make them secure.