1. A method of speaker dependent speech recognition, comprising: building a universal background model (UBM) for a user responsive to unknown speech from only the user; adapting the universal background model (UBM) to build a single Gaussian Mixture Model (GMM) responsive to a registration code phrase spoken by the user and using the single GMM to generate a code-phrase model (CPM) for the user; generating a longest common sequence (LCS) template for the user from the code-phrase model (CPM), wherein the LCS template is represented by a sequence of an index of a best performing component of the single GMM; utilizing the universal background model (UBM), code-phrase model (CPM) and longest common sequence (LCS) template to determine whether the user is an authorized user and has spoken the registration code phrase, the utilizing including, capturing a test code phrase; accepting the test code phrase as being spoken by the authorized user when the log likelihood ratio between the code-phrase model (CPM) and the universal background model (UBM) is positive; and comparing the Longest Common Sequence (LCS) template with a test code-phrase template for the captured test code phrase.