Update eth-secpm.md

vac/70/eth-secpm.md

@@ -17,7 +17,7 @@ Therefore a decentralized approach to secure communication becomes increasingly
 offering a robust solution to address these challenges.
 
 This specification outlines a private messaging service using the Ethereum blockchain as authentication service. 
-Rooted in the existing [model](https://rfc.vac.dev/spec/20/), 
+Rooted in the existing [model](../../waku/standards/application/20/toy-eth-pm.md), 
 this proposal addresses the deficiencies related to forward privacy and authentication inherent in the current framework.
 The specification is divided into 3 sections: