A computer implemented method to improve security in authentication/authorization systems, wherein a second server, in connection with a computing device of a user, via a second dedicated program installed in said computing device, is used to manage a status of the accounts the user has in a first server and a status of the operations defined for a particular account, said account status and said operation status being set, whenever the user wants, as valid or as invalid by the user via the second dedicated program and stored in a memory of the second server, and said account status and said operation status being set by the user once a pairing process with the second server being completed, said pairing process ensuring privacy to the user, the method comprising: - receiving, by said first server, from the user via a first dedicated program including a browser, a request to be logged into a service of said first server, said request including the provision of identification information validating the identity of the user in the first server; - authenticating, by said first server, said identification information of the user in order to authorize said service login request; - requesting, by the user via the first dedicated program, once the service login request being authenticated by the first server, to perform an operation in the first server associated with the requested service; - receiving, by the second server, from the first server, a request about an operation status associated to what said user has established about said requested operation in order to assist the first server in authorizing or rejecting the requested operation; - verifying, by the second server, said operation status previously established by the user for said requested operation; and - in response to said operation status being established as valid by the user, further performing either by the second server or by the first server an extra authentication factor mechanism for reinforcing authorization of said requested operation, wherein said extra authentication factor mechanism includes performing a public/private key encryption process to demonstrate that the user demanding the operation is in possession of the private key of a digital certificate or the use of a public/private key for generating a digital signature of an authentication token to show that the user demanding the operation is in possession of the private key of a digital certificate. - receiving, by said first server, from the user via a first dedicated program including a browser, a request to be logged into a service of said first server, said request including the provision of identification information validating the identity of the user in the first server; - authenticating, by said first server, said identification information of the user in order to authorize said service login request; - requesting, by the user via the first dedicated program, once the service login request being authenticated by the first server, to perform an operation in the first server associated with the requested service; - receiving, by the second server, from the first server, a request about an operation status associated to what said user has established about said requested operation in order to assist the first server in authorizing or rejecting the requested operation; - verifying, by the second server, said operation status previously established by the user for said requested operation; and - in response to said operation status being established as valid by the user, further performing either by the second server or by the first server an extra authentication factor mechanism for reinforcing authorization of said requested operation, wherein said extra authentication factor mechanism includes performing a public/private key encryption process to demonstrate that the user demanding the operation is in possession of the private key of a digital certificate or the use of a public/private key for generating a digital signature of an authentication token to show that the user demanding the operation is in possession of the private key of a digital certificate.