RSA: more than one secret exponent d exists ???

hi all,

In a given RSA system with public (n,e), how do I prove that there
exist more than
one possible secret exponent d that works ?
In other words, how can I show that there exists d' < phi(n), d' !=
e^(-1) mod(phi(n))
which correctly decrypts every message C =m^e modn ?

thanks alot!!
George

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