A method of online identification and authentication, comprising: generating, by a first user utilizing an identity contact expression application of a first device, a credential to represent a relationship between the first user and a second user based on a common ground of authenticated communication; exchanging the credential from the first device to a second device; with the identity contact expression application of the first device: generating, utilizing the credential, a public key hash value for the second user; generating, utilizing the credential, an identity hash value for the second user; generating a contact pair comprising the public key hash value and the identity hash value; characterized in that the method comprises: generating, utilizing the contact pair, a contact pair field including the contact pairs representing all of the users that share a common ground of authenticated communication with the first user; and generating, utilizing the contact pair field, an identity contact expression to represent a cumulative identity for the first user incorporating multiple grounds of authenticated communication, each ground corresponding to a distinct user identity for the first user. generating, by a first user utilizing an identity contact expression application of a first device, a credential to represent a relationship between the first user and a second user based on a common ground of authenticated communication; exchanging the credential from the first device to a second device; with the identity contact expression application of the first device: generating, utilizing the credential, a public key hash value for the second user; generating, utilizing the credential, an identity hash value for the second user; generating a contact pair comprising the public key hash value and the identity hash value; characterized in that the method comprises: generating, utilizing the contact pair, a contact pair field including the contact pairs representing all of the users that share a common ground of authenticated communication with the first user; and generating, utilizing the contact pair field, an identity contact expression to represent a cumulative identity for the first user incorporating multiple grounds of authenticated communication, each ground corresponding to a distinct user identity for the first user. generating, utilizing the credential, a public key hash value for the second user; generating, utilizing the credential, an identity hash value for the second user; generating a contact pair comprising the public key hash value and the identity hash value; characterized in that the method comprises: generating, utilizing the contact pair, a contact pair field including the contact pairs representing all of the users that share a common ground of authenticated communication with the first user; and generating, utilizing the contact pair field, an identity contact expression to represent a cumulative identity for the first user incorporating multiple grounds of authenticated communication, each ground corresponding to a distinct user identity for the first user. generating, utilizing the contact pair, a contact pair field including the contact pairs representing all of the users that share a common ground of authenticated communication with the first user; and generating, utilizing the contact pair field, an identity contact expression to represent a cumulative identity for the first user incorporating multiple grounds of authenticated communication, each ground corresponding to a distinct user identity for the first user.