Programmed computer for generating pronounceable security passwords

• US 5,850,448 A
• Filed: 10/15/1996
• Issued: 12/15/1998
• Est. Priority Date: 10/25/1994
• Status: Expired due to Term

• Current Assignee: Verizon Patent and Licensing Incorporated (Verizon Communications Inc.)
• Original Assignee: Bell Atlantic Network Services, Inc. (Verizon Communications Inc.)
• Inventors: Ganesan, Ravi
• Primary Examiner(s): CANGIALOSI, SALVATORE A
• Application Number:
  US08/731,427
• Time in Patent Office: 791 Days
• Field of Search: 380/1, 380/2, 380/23, 380/25, 380/4, 380/44
• US Class Current: 713/184
• CPC Class Codes: G06F 21/31 User authentication
• CPC Class Codes: G07F 7/10 together with a coded signal , e.g. in the form of personal identification information, like personal identification number [PIN] or biometric data

Abstract

A programmed computer for forming a pronounceable security password, includes storage medium having a plurality of first and second word segment portions stored thereon. Each second word segment portion is within one or more sets of second word segment portions, each set being associated with one first word segment portion. Each second word segment portion within a particular set is different from others within the set and is combinable with the associated first word segment portion to form a pronounceable word segment. A plurality of transition numbers each associated with one or more of the first word segment portions and corresponding to the number of said second word segment portions within the associate set of second word segment portions are also stored on the storage medium. The computer includes a processor programmed to select a first word segment portion and a second word segment portion from its associated set of second word segment portions. Selection of any one of the first word segment portions and any one of the second word segment portions within the associated set is of substantially equal probability. The processor combines the selected first and second word segment portions to form a first pronounceable word segment and determines if consecutive characters thereof are unacceptable based upon their correspondence to those of the first word segment portions having a transition number less than a threshold. If acceptable a pronounceable security password of eight or more characters is generated so as to include the first pronounceable word segment.

Claims

1. An article of manufacture for forming a pronounceable security password using a plurality of first word segment portions and a plurality of second word segment portions, with each of said plurality of first word segment portions having (i) an associated set of one or more said second word segment portions, each said second word segment portion within said associated set being different from others within said set and being combinable with said associated first word segment portion to form a pronounceable word segment and (ii) a transition number corresponding to the number of said second word segment portions within the associated set of second word segment portions, comprising:

computer readable storage medium; and

computer programming stored on said storage medium;

wherein said stored computer programming is configured to be readable from said computer readable storage medium by a computer and thereby cause said computer to operate so as to;

select a first one of said plurality of first word segment portions, wherein selection of any one of said plurality of first word segment portions is of substantially equal probability;

select a first one of said plurality of second word segment portions from said set of second word segment portions associated with said selected first word segment portion, wherein selection of any one of said second word segment portions within said associated set of second word segment portions is of substantially equal probability;

combine said selected first word segment portion and said selected second word segment portion to form a first pronounceable word segment;

determine if consecutive characters of said first pronounceable word segment are unacceptable due to their correspondence to those of said plurality of first word segment portions having a transition number less than a first threshold transition number; and

generate a pronounceable security password of eight or more characters including said first pronounceable word segment only if consecutive characters of said first pronounceable word segment are determined to be acceptable.

2. An article of manufacture for forming a pronounceable security password according to claim 1, wherein said stored computer programming is configured to be readable from said computer readable storage medium by the computer to thereby cause said computer to operate so as to:

discard said first pronounceable word segment if the consecutive characters are determined to be unacceptable;

select a second one of said plurality of first word segment portions, wherein selection of any one of said plurality of first word segment portions is of substantially equal probability;

select a second one of said plurality of second word segment portions from the set of second word segment portions associated with said second selected first word segment portion, wherein selection of any one of said second word segment portions within said associated set of second word segment portions is of substantially equal probability;

combine said second selected first word segment portion and said second selected second word segment portion to form a substitute first pronounceable word segment;

determine if consecutive characters of said substitute first pronounceable word segment are unacceptable due to their correspondence to those of said plurality of first word segment portions having a transition number less than the first threshold transition number; and

generate a pronounceable security password of eight or more characters including said substitute first pronounceable word segment only if consecutive characters of said substitute first pronounceable word segment are determined to be acceptable.

3. An article of manufacture for forming a pronounceable security password according to claim 1, wherein said selected first word segment portion is a bigram or a trigram.

4. An article of manufacture for forming a pronounceable security password according to claim 1, wherein said stored computer programming is configured to be readable from said computer readable storage medium by the computer to thereby cause said computer to operate so as to:

identify a first word segment portion, within said plurality of first word segment portions, corresponding to one or more characters at an end portion of said first pronounceable word segment;

select a second one of said plurality of second word segment portions from the set of second word segment portions associated with said corresponding first word segment portion, wherein selection of any one of said second word segment portions within said associated set of second word segment portions is of substantially equal probability;

combine said first pronounceable word segment with said second selected second word segment portion to form a part of the password; and

determine if consecutive characters of the formed password part are unacceptable due to their correspondence to those of said plurality of first word segment portions having a transition number less than a second threshold transition number;

wherein the generated pronounceable security password includes said second selected second word segment only if the consecutive characters of the password part are determined to be acceptable.

5. An article of manufacture for forming a pronounceable security password according to claim 4, wherein said second threshold transition number is different than said first threshold transition number.

6. An article of manufacture for forming a pronounceable security password according to claim 1, wherein said stored computer programming is configured to be readable from said computer readable storage medium by the computer to thereby cause said computer to operate so as to:

select a second one of said plurality of first word segment portions, wherein selection of any one of said plurality of first word segment portions is of substantially equal probability;

select a second one of said second word segment portions from the set of second word segment portions associated with said second selected first word segment portion, wherein selection of any one of said second word segment portions within said associated set of second word segment portions is of substantially equal probability;

combine said second selected first word segment portion and said second selected second word segment portion to form a second pronounceable word segment;

combine said first pronounceable word segment with said second pronounceable word segment to form at least a part of the password; and

determine if consecutive characters of the formed password part are unacceptable due to their correspondence to those of said plurality of first word segment portions having a transition number less than a second threshold transition number;

wherein the generated pronounceable security password includes said second pronounceable word segment only if consecutive characters of the formed password part are determined to be acceptable.

7. An article of manufacture for forming a pronounceable security password according to claim 6, wherein said second threshold transition number is different than said threshold transition number.

8. An article of manufacture for forming a pronounceable security password according to claim 6, wherein said stored computer programming is configured to be readable from said computer readable storage medium by the computer to thereby cause said computer to operate so as to:

discard said second pronounceable word segment if consecutive characters of the formed password part are determined to be unacceptable;

select a third one of said plurality of first word segment portions, wherein selection of any one of said plurality of first word segment portions is of substantially equal probability;

select a third one of said plurality of second word segment portions from the set of second word segment portions associated with said third selected first word segment portion, wherein selection of any one of said second word segment portions within said associated set of second word segment portions is of substantially equal probability;

combine said third selected first word segment portion and said third selected second word segment portion to form a substitute second pronounceable word segment;

combine said first pronounceable word segment and said substitute second pronounceable word segment to form a substitute part of the password; and

determine if consecutive characters of the substitute password part are unacceptable due to their correspondence to those of said plurality of first word segment portions having a transition number less than the second threshold transition number;

wherein the generated pronounceable security password includes said substitute second pronounceable word segment only if the consecutive characters of the substitute password part are determined to be acceptable.

9. An article of manufacture for forming a pronounceable security password according to claim 1, wherein said stored computer programming is configured to be readable from said computer readable storage medium by the computer to thereby cause said computer to operate so as to:

apply said pronounceable security password to encrypt or decrypt a message.

10. An article of manufacture for forming a pronounceable security password using a plurality of first word segment portions and a plurality of second word segment portions, each of said plurality of first word segment portions having an associated set of one or more said second word segment portions and being categorized into one of at least two categories based upon a transition number corresponding to the number of said second word segment portions within the associate set of second word segment portions, and each said second word segment portion within said associated set being different from others within said set and being combinable with said associated first word segment portion to form a pronounceable word segment comprising:

computer readable storage medium; and

computer programming stored on said storage medium;

wherein said stored computer programming is configured to be readable from said computer readable storage medium by a computer and thereby cause said computer to operate so as to;

select a first one of said plurality of first word segment portions categorized within one or more categories selected from said at least two categories, wherein the transition number associated with each of said first word segment portions categorized within said selected categories equals or exceeds a first threshold transition value and selection of any one of said plurality of first word segment portions categorized within said selected categories is of substantially equal probability;

select a first one of said plurality of second word segment portions from the set of second word segment portions associated with the selected first word segment portion, wherein selection of any one of said second word segment portions within said associated set of second word segment portions is of substantially equal probability;

combine said selected first word segment portion and said selected second word segment portion to form a first pronounceable word segment;

determine if consecutive characters of said first pronounceable word segment are unacceptable due to their correspondence to those of said plurality of first word segment portions categorized in a non-selected category; and

generate a pronounceable security password of eight or more characters and including said first pronounceable word segment only if the consecutive characters of the first pronounceable word segment are determined to be acceptable.

11. An article of manufacture for forming a pronounceable security password according to claim 10, wherein the transition number associated with each of said first word segment portions categorized within said selected categories is higher than the transition number associated with each of said first word segment portions categorized in a non-selected category.

12. An article of manufacture for forming a pronounceable security password according to claim 11, wherein said stored computer programming is configured to be readable from said computer readable storage medium by the computer to thereby cause said computer to operate so as to:

discard said first selected second word segment portion if the consecutive characters of said first pronounceable word segment portion are determined to be unacceptable;

select a second one of said plurality of second word segment portions from the set of second word segment portions associated with the selected first word segment portion, wherein selection of any one of said second word segment portions within said associated set of second word segment portions is of substantially equal probability;

combine said selected first word segment portion and said second selected second word segment portion to form a substitute first pronounceable word segment;

determine if consecutive characters of said substitute first pronounceable word segment are unacceptable due to their correspondence to those of said plurality of first word segment portions categorized in a non-selected category; and

generate a pronounceable security password of eight or more characters and including said substitute first pronounceable word segment only if consecutive characters of the substitute first pronounceable word segment are determined to be acceptable.

13. An article of manufacture for forming a pronounceable security password according to claim 10, wherein said stored computer programming is configured to be readable from said computer readable storage medium by the computer to thereby cause said computer to operate so as to:

identify a first word segment portion, within said plurality of first word segment portions categorized in said selected categories and corresponding to consecutive characters at an end portion of said first pronounceable word segment;

select a second of said plurality of second word segment portions from the set of second word segment portions associated with said corresponding first word segment portion, wherein selection of any one of said second word segment portions within said associated set of second word segment portions is of substantially equal probability;

combine said first pronounceable word segment with said second selected second word segment portion to form a part of said password; and

determine if consecutive characters of said formed password part are unacceptable due to their correspondence to those of said plurality of first word segment portions categorized in a non-selected category,

wherein the generated pronounceable security password includes said selected other second word segment portion only if the consecutive characters of the formed password part are determined to be acceptable.

14. An article of manufacture for forming a pronounceable security password according to claim 10, wherein said stored computer programming is configured to be readable from said computer readable storage medium by the computer to thereby cause said computer to operate so as to:

select a second one of said plurality of first word segment portions categorized within said selected categories, wherein selection of any one of said first word segment portions categorized within said one or more selection categories is of substantially equal probability;

select a second one of said plurality of second word segment portions from the set of second word segment portions associated with the second selected first word segment portion, wherein selection of any one of said second word segment portions within said associated set of second word segment portions is of substantially equal probability;

combine said second selected first word segment portion and said second selected second word segment portion to form a second pronounceable word segment;

combine said first pronounceable word segment with said second pronounceable word segment to form a portion of said password; and

determine if consecutive characters of said formed password portion are unacceptable due to their correspondence to those of said plurality of first word segment portions categorized in a non-selected category;

wherein the generated pronounceable security password includes said second pronounceable word segment portion only if consecutive characters of the formed password portion are determined to be acceptable.

15. An article of manufacture for forming a pronounceable security password according to claim 14, wherein said stored computer programming is configured to be readable from said computer readable storage medium by the computer to thereby cause said computer to operate so as to:

discard said second pronounceable word segment if the consecutive characters of the formed password portion are determined to be unacceptable;

select a third one of said plurality of first word segment portions categorized within said selected categories, wherein selection of any one of said first word segment portions categorized within said selected categories is of substantially equal probability;

select a third one of said plurality of second word segment portions from the set of second word segment portions associated with the third selected first word segment portion, wherein selection of any one of said second word segment portions within said associated set of second word segment portions is of substantially equal probability;

combine said third selected first word segment portion and said third selected second word segment portion to form a substitute second pronounceable word segment;

combine said first pronounceable word segment and said substitute second pronounceable word segment to form a substitute portion of said password; and

determine if consecutive characters of said formed substitute password portion are unacceptable due to their correspondence to those of said plurality of first word segment portions categorized in a non-selected category,

wherein the generated pronounceable security password includes said substitute second pronounceable word segment only if consecutive characters of the formed substitute password are determined to be acceptable.

16. An article of manufacture for forming a pronounceable security password according to claim 10, wherein the selected first word segment portion is a bigram or a trigram.

17. An article of manufacture for forming a pronounceable security password using a plurality of pronounceable word segments, each of said plurality of word segments including a first portion and a second portion and being categorized into one of at least two categories based upon a transition number corresponding to the number of different said second portions included in those of said plurality of word segments which have a first portion identical to the first portion of the word segment being categorized, comprising:

computer readable storage medium; and

computer programming stored on said storage medium;

wherein said stored computer programming is configured to be readable from said computer readable storage medium by a computer and thereby cause said computer to operate so as to;

select at least two of said word segments categorized within one or more categories selected from said at least two categories, wherein the transition number associated with each of said word segment portions categorized within said selected categories equals or exceeds a first threshold transition number and the probability of selection of any one of said word segments categorized within said selected categories is substantially equal; and

combine said selected word segments to form a portion of said pronounceable security password;

determine if consecutive characters of said formed pronounceable security password portion are unacceptable based upon their correspondence to those of said plurality of first word segment portions categorized in a non-selected category; and

generate a pronounceable security password of eight or more characters and including said formed pronounceable security password portion only if the consecutive characters of said pronounceable security password portion are determined to be acceptable.

18. An article of manufacture for forming a pronounceable security password according to claim 17, wherein the transition number associated with each said word segment categorized in said selected categories is higher than the transition number associated with each said word segment categorized in a non-selected category.

19. An article of manufacture for generating a pronounceable security password comprising:

computer readable storage medium; and

computer programming stored on said storage medium;

wherein said stored computer programming is configured to be readable from said computer readable storage medium by a computer and thereby cause said computer to operate so as to;

divide each of a plurality of pronounceable word segments into a first portion having at least one character and a second portion having at least one character;

determine a probability of transition of each of said first portions to one or more of said second portions to form one of the pronounceable word segments;

randomly select one of said first portions from those of said first portions having a probability of transition less than a threshold;

randomly select one of said second portions from those of said second portions combinable with said selected first portion to form one of said pronounceable word segments;

combine said selected first and said selected second portions to form one of said pronounceable word segments;

determine if consecutive characters of said formed pronounceable word segment are unacceptable based upon their correspondence to those of said first portions which have an associated probability of transition which is greater than the selected threshold; and

generate a pronounceable security password including said pronounceable word segment only if consecutive characters of said formed pronounceable word segment are determined to be acceptable.

20. A article of manufacture for generating a pronounceable security password according to claim 19, wherein said stored computer programming is configured to be readable from said computer readable storage medium by the computer to thereby cause said computer to operate so as to:

categorize said first portions into multiple categories based upon said probability of transition; and

randomly select the selected first portion only from said first portions categorized within selected of said categories.

21. An article of manufacture for generating a pronounceable security password according to claim 19, wherein said probability of transition is determined using a second or third order Markov model.

22. A programmed computer for forming a pronounceable security password, comprising:

storage medium having stored (i) a plurality of first word segment portions, (ii) a plurality of second word segment portions, each second word segment portion being within one or more sets of second word segment portions with each of said sets being associated with one first word segment portion and each second word segment portion within a particular associated set being different from others within said particular associated set and being combinable with the associated first word segment portion to form a pronounceable word segment and (iii) a plurality of transition numbers each associated with one or more of the plurality of first word segment portions and corresponding to the number of said second word segment portions within the associate set of second word segment portions;

a processor configured to (i) select a first one of said plurality of first word segment portions, wherein selection of any one of said plurality of first word segment portions is of substantially equal probability, (ii) select a first one of said plurality of second word segment portions from said set of second word segment portions associated with said selected first word segment portion, wherein selection of any one of said second word segment portions within said associated set of second word segment portions is of substantially equal probability, (iii) combine said selected first word segment portion and said selected second word segment portion to form a first pronounceable word segment, (iv) determine if consecutive characters of said first pronounceable word segment are unacceptable based upon their correspondence to those of said plurality of first word segment portions having a transition number less than a first threshold transition number, and (v) generate a pronounceable security password of eight or more characters and including said first pronounceable word segment only if the consecutive characters of said first pronounceable word segment are determined to be acceptable.

23. A programmed computer for forming a pronounceable security password according to claim 22, wherein said processor is configured to:

discard said first pronounceable word segment if the consecutive characters of the first pronounceable word segment are determined to be unacceptable,

select a second one of said plurality of first word segment portions, wherein selection of any one of said plurality of first word segment portions is of substantially equal probability,

select a second one of said plurality of second word segment portions from the set of second word segment portions associated with said second selected first word segment portion, wherein selection of any one of said second word segment portions within said associated set of second word segment portions is of substantially equal probability,

combine said second selected first word segment portion and said second selected second word segment portion to form a substitute first pronounceable word segment,

determine if consecutive characters of said substitute first pronounceable word segment are unacceptable based upon their correspondence to those of said plurality of first word segment portions having a transition number less than the first threshold transition number, and

generate a pronounceable security password including said substitute first pronounceable word segment only if consecutive characters of the substitute first pronounceable word segment are determined to be acceptable.

24. A programmed computer for forming a pronounceable security password according to claim 22, wherein said processor is configured to:

identify a first word segment portion, within said plurality of first word segment portions, corresponding to one or more characters at an end portion of said first pronounceable word segment;

select a second one of said plurality of second word segment portions from the set of second word segment portions associated with said corresponding first word segment portion, wherein selection of any one of said second word segment portions within said associated set of second word segment portions is of substantially equal probability,

combine said first pronounceable word segment with said second selected second word segment portion to form a part of the password, and

determine if consecutive characters of said password part are unacceptable based upon their correspondence to those of said plurality of first word segment portions having a transition number less than a second threshold transition number,

wherein the generated pronounceable security password includes said second selected second word segment only if consecutive characters of the password part are determined to be acceptable.

25. A programmed computer for forming a pronounceable security password according to claim 24, wherein said second threshold transition number is different than said first threshold transition number.

26. A programmed computer for forming a pronounceable security password according to claim 22, wherein said processor is configured to:

select a second one of said plurality of first word segment portions, wherein selection of any one of said plurality of first word segment portions is of substantially equal probability,

select a second one of said second word segment portions from the set of second word segment portions associated with said second selected first word segment portion, wherein selection of any one of said second word segment portions within said associated set of second word segment portions is of substantially equal probability,

combine said second selected first word segment portion and said second selected second word segment portion to form a second pronounceable word segment,

combine said first part of the password with said second part of the password to form a portion of the password, and

determine if consecutive characters of said password portion are unacceptable based upon their correspondence to those of said plurality of first word segment portions having a transition number less than a second threshold transition number,

wherein the generated pronounceable security password includes said second pronounceable word segment only if the consecutive characters of the password portion are determined to be acceptable.

27. A programmed computer for forming a pronounceable security password according to claim 26, wherein said second threshold transition number is different than said threshold transition number.

28. A programmed computer for forming a pronounceable security password according to claim 22, wherein:

said selected first word segment portion is a bigram or a trigram,

said processor is configured to apply said pronounceable security password to encrypt or decrypt a message, and

said storage medium has said first threshold value stored thereon.

29. A programmed computer for forming a pronounceable security password, comprising:

storage medium having stored (i) a plurality of first word segment portions, each being categorized into one of a plurality of categories based upon a transition number corresponding to the number of different second word segment portions within an associated set of second word segment portions formed from a plurality of second word segment portions which are combinable with the associated first word segment portion to form a pronounceable word segment, and (ii) the plurality of second word segment portions; and

a processor configured to (i) select a first one of said plurality of first word segment portions categorized within a selected one or more of said plurality of categories, wherein the transition number associated with each of said first word segment portions categorized within said one or more selected categories equals or exceeds a first threshold transition value and selection of any one of said plurality of first word segment portions categorized within said one or more selected categories is of substantially equal probability, (ii) select a first one of said plurality of second word segment portions from the set of second word segment portions associated with the selected first word segment portion, wherein selection of any one of said second word segment portions within said associated set of second word segment portions is of substantially equal probability, (iii) combine said selected first word segment portion and said selected second word segment portion to form a first pronounceable word segment, (iv) determine if consecutive characters of said first pronounceable word segment are unacceptable based upon their correspondence to those of said plurality of first word segment portions categorized in a non-selected category, and (v) generate a pronounceable security password of eight or more characters including said first pronounceable word segment only if the consecutive characters of the first pronounceable word segment are determined to be acceptable.

30. A programmed computer for forming a pronounceable security password according to claim 29, wherein the transition number associated with each of said first word segment portions categorized within said one or more selected categories is higher than the transition number associated with each of said first word segment portions categorized in non-selected categories.

31. A programmed computer for forming a pronounceable security password according to claim 29, wherein said processor is configured to:

discard said first selected second word segment portion if the consecutive characters of said first pronounceable word segment portion are determined to be unacceptable,

select a second one of said plurality of second word segment portions from the set of second word segment portions associated with the selected first word segment portion, wherein selection of any one of said second word segment portions within said associated set of second word segment portions is of substantially equal probability,

combine said selected first word segment portion and said second selected second word segment portion to form a substitute first pronounceable word segment,

determine if consecutive characters of said substitute first pronounceable word segment are unacceptable based upon their correspondence to those of said plurality of first word segment portions categorized in a non-selected category, and

wherein the generated pronounceable security password includes said substitute first pronounceable word segment only if the consecutive characters of the substitute first pronounceable word segment are determined to be acceptable.

32. A programmed computer for forming a pronounceable security password according to claim 29, wherein said processor is configured to:

identify a first word segment portion within said plurality of first word segment portions categorized in said one or more selected categories and corresponding to consecutive characters at an end portion of said first pronounceable word segment,

select a second of said plurality of second word segment portions from the set of second word segment portions associated with said corresponding first word segment portion, wherein selection of any one of said second word segment portions within said associated set of second word segment portions is of substantially equal probability;

combine said first pronounceable word segment with said second selected second word segment portion to form a part of said password; and

determine if consecutive characters of said formed password part are unacceptable based upon their correspondence to those of said plurality of first word segment portions categorized in a non-selected category,

wherein the generated pronounceable security password includes said second selected second word segment portion only if the consecutive characters of the formed password part are determined to be acceptable.

33. A programmed computer for forming a pronounceable security password according to claim 29, wherein said processor is configured to:

select a second one of said plurality of first word segment portions categorized within a second selected one or more of said plurality of categories, wherein the transition number associated with each of said first word segment portions categorized within said one or more second selected categories equals or exceeds a second threshold transition value and selection of any one of said first word segment portions categorized within said one or more selection categories is of substantially equal probability;

select a second one of said plurality of second word segment portions from the set of second word segment portions associated with the second selected first word segment portion, wherein selection of any one of said second word segment portions within said associated set of second word segment portions is of substantially equal probability;

combine said second selected first word segment portion and said second selected second word segment portion to form a second pronounceable word segment;

combine said first pronounceable word segment with said second pronounceable word segment to form a portion of said password; and

determine if consecutive characters of said password portion are unacceptable based upon their correspondence to those of said plurality of first word segment portions categorized in a non-selected category;

wherein the generated pronounceable security password includes said second pronounceable word segment only if the consecutive characters of the password portion are determined to be acceptable.

34. A programmed computer for forming a pronounceable security password according to claim 33, wherein the second threshold transition value is less than the first threshold transition value and the storage medium stores a parameter corresponding to the first selected categories and the second selected categories.

35. A programmed computer for forming a pronounceable security password according to claim 29, wherein each of the plurality of first word segment portions is a bigram or a trigram.

36. A programmed computer for forming a pronounceable security password using a plurality of pronounceable word segments, comprising:

storage medium having stored (i) a plurality of word segments each having first and second portions and being categorized into one of a plurality of categories based upon a transition number corresponding to the number of different second portions included in those of said plurality of word segments which have a first portion identical to the first portion of the word segment being categorized; and

a processor configured to (i) select at least two of said word segments categorized within one or more categories selected from said plurality of categories, wherein the transition number associated with each of said word segment portions categorized within said selected categories equals or exceeds a first threshold transition number and the probability of selection of any one of said word segments categorized within said selected categories is substantially equal, (ii) combine said selected word segments to form a portion of said pronounceable security password, (iii) determine if consecutive characters of said pronounceable security password portion are unacceptable based upon their correspondence to those of said plurality of first word segment portions categorized in a non-selected category, and (iv) generate a pronounceable security password of eight or more characters and including said pronounceable security password portion only if the consecutive characters of said pronounceable security password portion are determined to be acceptable.

37. A programmed computer for forming a pronounceable security password according to claim 36, wherein the transition number associated with each said word segment categorized in said selected one or more categories is higher than the transition number associated with each said word segment categorized in a non-selected category.

38. A programmed computer for forming a pronounceable security password comprising:

a processor configured to (i) divide each of a plurality of pronounceable word segments into a first portion having at least one character and a second portion having at least one character, (ii) determine a probability of transition from each said first portion to one or more of said second portions to form the pronounceable word segments, (iii) randomly select one of said first portions from those of said first portions having a probability of transition equal to or less than a threshold, for use in the pronounceable security password, (iv) randomly select one of said second portions from those of said second portions combinable with said selected first portion to form one of said pronounceable word segments, (v) combine said selected first and said selected second portions to form one of said pronounceable word segments, (vi) determine if consecutive characters of said formed pronounceable word segment are acceptable based upon their correspondence to those of said first portions which have an associated probability of transition which is greater than the threshold, and (vii) generate a pronounceable security password including said pronounceable word segment only if consecutive characters of the formed pronounceable word segment are determined to be acceptable; and

storage medium configured to store said first portions and said second portions.

39. A programmed computer for generating a pronounceable security password according to claim 38, wherein said processor is configured to:

categorize said first portions into a plurality of categories based upon said probabilities of transition; and

randomly select the selected first portion only from those of said first portions categorized within selected of said categories.

40. An programmed computer for generating a pronounceable security password according to claim 38, wherein said probability of transition is determined using a second or third order Markov model.