Submitted on: 04 March 2000.
Revised on: 16 April 2000.
Accepted on: 06 May 2000.
___________________Journal of Mathematical Cryptology
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Submitted on: 07 July 2000.
Revised on: 29 October 2000.
Accepted on: 20 November 2000.
___________________Journal of Mathematical Cryptology
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Submitted on: 17 November 1999.
Revised on: 07 December 1999.
Accepted on: 21 December 1999.
___________________Journal of Mathematical Cryptology
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Submitted on: 21 January 1998.
Revised on: 12 February 1998.
Accepted on: 23 February 1998.
___________________Journal of Mathematical Cryptology
Submitted on: 27 January 1998.
Revised on: 05 May 1998.
Accepted on: 15 May 1998.
___________________Journal of Mathematical Cryptology
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