What a puzzle!

In February just before the reading week ((20-25)-02-1995), we posted a piece of news to both hku.open-forum in Computer Centre news servers. It reads:

Tue, 14 Feb 1995 16:56:10 openforum Lines 57 A thrill for your reading week... Hi, We're students from a Computer Science Department course 'Topics in Networking' which currently talks about network security. Recently we've came up with an assignment problem that required us to decrypt a 204 character string to a readable and meaningful message. That was both fun and pain for us. Whether we have spent five hours or five days to do the assignment, anyway we decrypted it. And it was so relieving after doing so. So here we've produced another sequence of characters for you to share the fun we have. It's an open game to all in HKU who has email access, whether you're a student or a lecturer. We will give out a little token of appreciation for the first three who can successfully decrypt the following message: -=i'|l-+|''|_.1*|[]i--(_]-=(l1''|_(1(l-|.1(-1^1*|)-.|1[-i)li--(_]!~-=i-1_:l |-=1-+=;|)(_i+1_^(ll(~1-i'1:il!)i-=1-*|!).1-i)(l+;i1)1_^-=i_~!-(_1[i.=1)^*1 _^(_i,~i_l(>i[(l=-=i[(l=.1l-i+|_-1(_l-=i1''|_(1|_.=(+=-=i<1+-i)(1;(>i Also, we'll have your name posted in the newsgroups so that others will know who got the honour. Relax, it is not our assignment problem. Don't be scared by the length of the string; indeed, the longer it is, the easier the decryption can be done. Here are some hints: * The newlines shown above do not have special meanings; they're just there so that the character sequence looks less messy. * The original text is in English. * Simple substitution is used to transform the original characters to the encrypted string. e.g., hello {h->b e->l l->o o->m} becomes bloom * Which is the most frequently occuring English character in normal text? Which is the second? You can use whatever method, with the help of computer or not, to decrypt the message. If you can decrypt it, please send the following: * The mapping table: which character should correspond to which. e.g., ciphertext - = i ......etc plaintext b c x ......etc * The decrypted message written so that one can read it sensibly. e.g., The original message is: This is a test of your patience ......etc. to jckyau@csd.hku.hk or clyip@csd.hku.hk and we'll acknowledge your entry and give the prize if you are one of the first three who can decrypt the message. Have fun! Regards, Joe Yau. <jckyau@csd.hku.hk> Beta. <clyip@csd.hku.hk>

There was good response to the piece of news. On Thursday 16-02-1995 we posted: 

Hello All,

        The count for successful participants for solving the puzzle
        has been bumped up to 3 now.  They are:

	Prudence Wong <whwong@csis.hku.hk>
        Mail sent on: Wed, 15 Feb 1995 23:40:26 +0800 (HKT)

	K.M.Poon <kmpoon%hkueee@hkueee.eee.hku.hk>
        Mail sent on: Thu Feb 16 01:37:27 1995

	Doug Kwan <ctkwan@stamina.csis.hku.hk>
        Mail sent on: Thu, 16 Feb 1995 16:26:52 +0800

        So, let's cheer for these participants.....(yeah!!!)

        Prizes for these participants will be awarded later!

        Thank you for you participation, and we look forward
        to greet you with some other puzzle.....

        Until next time.....

--
jckyau@csd.hku.hk......Joe Yau

A city is a large community where people are lonesome together!
                                         -- H. Prochnow

The prize giving ceremony was held on 20-02-1995 in System Research Group (SRG) Lab, room 823, Knowles Building, HKU.

The prizes are: