A computer-implemented method for secure user authentication in electronic commerce, comprising: maintaining electronic information having a first aspect and a second aspect, said first aspect being accessible by a user over a first electronic communication channel in response to entry of a first credential known to the user and said second aspect being accessible by the user over the first electronic communication channel in response to entry of a second credential provided to the user; pre-registering a delivery address on a second electronic communication channel that is different from the first electronic communication channel for providing the second credential to the user; allowing a user a current session of access to the first aspect of the electronic information in response to entry of the first credential and providing the second credential to the user at the pre-registered delivery address via the second electronic communication channel in response to entry of a pre-determined user selection during said session of user access to the first aspect, wherein a change in the user's delivery address on said second electronic communication channel results in that a flag is set on a stored profile prohibiting providing of the second credential to the user, wherein said flag is set to expire after a pre-determined period of time, and allowing the user a session of access to the second aspect of the electronic information via the first electronic communication channel in response to entry of the second credential during one of said current session of user access to the first aspect and a succeeding session of user access to the first aspect. maintaining electronic information having a first aspect and a second aspect, said first aspect being accessible by a user over a first electronic communication channel in response to entry of a first credential known to the user and said second aspect being accessible by the user over the first electronic communication channel in response to entry of a second credential provided to the user; pre-registering a delivery address on a second electronic communication channel that is different from the first electronic communication channel for providing the second credential to the user; allowing a user a current session of access to the first aspect of the electronic information in response to entry of the first credential and providing the second credential to the user at the pre-registered delivery address via the second electronic communication channel in response to entry of a pre-determined user selection during said session of user access to the first aspect, wherein a change in the user's delivery address on said second electronic communication channel results in that a flag is set on a stored profile prohibiting providing of the second credential to the user, wherein said flag is set to expire after a pre-determined period of time, and allowing the user a session of access to the second aspect of the electronic information via the first electronic communication channel in response to entry of the second credential during one of said current session of user access to the first aspect and a succeeding session of user access to the first aspect.