A method comprising: transmitting, by a computing device to an authentication device (504, 506), a request to authenticate a client device application via a forms login protocol; the method characterised in further comprising: retrieving, by the computing device from the authentication device, a first credential form requesting a first authentication credential in which the first credential form is associated with a first authentication service, and a second credential form requesting a second authentication credential in which the second credential form is associated with a second authentication service, wherein the first credential form is generated, by an extension device connected to the authentication device, based on information received from an authentication service associated with the client device application, the extension device being configured with one or more authentication protocols of the authentication service associated with the client device application; combining the first and the second credential forms into a third credential form; transmitting, by the computing device to the client device application, the third credential form; receiving, by the computing device from the client device application, the first authentication credential and the second authentication credential; transmitting, by the computing device to the authentication service via the extension device, the first authentication credential and the second authentication credential; and transmitting, by the computing device and in response to a successful validation of the first authentication credential and the second authentication credential, an approval of the request made by the client device application to authenticate via the forms login protocol. transmitting, by a computing device to an authentication device (504, 506), a request to authenticate a client device application via a forms login protocol; the method characterised in further comprising: retrieving, by the computing device from the authentication device, a first credential form requesting a first authentication credential in which the first credential form is associated with a first authentication service, and a second credential form requesting a second authentication credential in which the second credential form is associated with a second authentication service, wherein the first credential form is generated, by an extension device connected to the authentication device, based on information received from an authentication service associated with the client device application, the extension device being configured with one or more authentication protocols of the authentication service associated with the client device application; combining the first and the second credential forms into a third credential form; transmitting, by the computing device to the client device application, the third credential form; receiving, by the computing device from the client device application, the first authentication credential and the second authentication credential; transmitting, by the computing device to the authentication service via the extension device, the first authentication credential and the second authentication credential; and transmitting, by the computing device and in response to a successful validation of the first authentication credential and the second authentication credential, an approval of the request made by the client device application to authenticate via the forms login protocol. retrieving, by the computing device from the authentication device, a first credential form requesting a first authentication credential in which the first credential form is associated with a first authentication service, and a second credential form requesting a second authentication credential in which the second credential form is associated with a second authentication service, wherein the first credential form is generated, by an extension device connected to the authentication device, based on information received from an authentication service associated with the client device application, the extension device being configured with one or more authentication protocols of the authentication service associated with the client device application; combining the first and the second credential forms into a third credential form; transmitting, by the computing device to the client device application, the third credential form; receiving, by the computing device from the client device application, the first authentication credential and the second authentication credential; transmitting, by the computing device to the authentication service via the extension device, the first authentication credential and the second authentication credential; and transmitting, by the computing device and in response to a successful validation of the first authentication credential and the second authentication credential, an approval of the request made by the client device application to authenticate via the forms login protocol.