Patent ID: 8239326

Claim:
A system, comprising: a processor; and a memory comprising program instructions, wherein the program instructions are executable by the processor to implement a transaction authorization service configured to: receive a message indicating initiation of a transaction between a source entity and a target entity, wherein the message is received via a first communications channel; send an authorization request message indicating a request for authorization of the transaction to a communications device of the source entity via a second communications channel, wherein the authorization request message is not sent to the target entity; determine that the authorization request message was not responded to by the source entity; in response to said determining that the authorization request message was not responded to by the source entity, generate a transaction phrase for the transaction, wherein the transaction phrase uniquely identifies the transaction to the transaction authorization service; send a message indicating the transaction phrase to the source entity; receive a message from the source entity, wherein the message from the source entity includes the transaction phrase to identify the transaction; and in response to said receiving the message including the transaction phrase from the source entity, resend the authorization request message indicating the request for authorization of the same transaction to the communications device of the source entity via the same second communications channel.