Integration to Salesforce through REST API without using consumer secret/key

I am trying to connect with the Salesforce via API call. I got the access token first by providing username, password, consumer key, consumer secret, grant_type. Then I used the access token and made the second call which is the actual API call for salesforce.
My question is, Is it possible to connect the Salesforce just using access token, username and password without really providing the consumer key and consumer secret or we definitely need the consumer key and consumer secret to connect with Salesforce.
We are using REST API and I don't want to use consumer key and consumer secret. Please suggested how to achieve this.