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From: Ben Bacarisse <ben.usenet@bsb.me.uk>
Newsgroups: comp.programming
Subject: Re: bike locks and encryption
Date: Tue, 07 Oct 2014 16:24:25 +0100
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Richard Heathfield <invalid@see.sig.invalid> writes:

> Ben Bacarisse wrote:
>
>> RichD <r_delaney2001@yahoo.com> writes:
>> 
>>> Something occurred to me recntly - bicycle locks
>>> as examples of one way functions, so useful in
>>> encryption.  That is, easy to compute in encryption,
>>> but intractable for decrytion, lacking the key.
>> 
>> I don't think that's a good analogy for a one-way function.  Although
>> all one-way functions have, in some very abstract sense, a "key" (the
>> function's inverse is, I suppose, a key) they are not, usually,
>> invertable with some small amount of data acting as a key.
>
> I think RSA is a counter-example, isn't it? (More on that in a
> second.)

I think you (and the OP) might be confusing trap-door functions with
one-way functions.

<snip>
-- 
Ben.