A method, a router and a host are introduced for providing secure communication with limited use of processing intensive cryptographic means. Strong cryptographic keys are first used between the host and the router to sign messages therebetween, thereby ensuring that a first communication between the host and the router is secure. The router generates a secret key and forwards it to the host, the secret key being encrypted at the router and decrypted at the host by use of the strong cryptographic keys. Further communication between the host and the router is signed by use of the secret key.