The affine cipher is the simple substitution cipher that you see in the hint section of every geocache listing. The affine cipher converts text to the corresponding numerical values of the letters (A=0, B=1, C=2, ..., Z=25), then encrypted with a mathematical function and finally converted back to the appropriate letters. The mathematical function that is used is the following: (ax+b) mod(26), where a and b are the keys of the cipher.
opsuiuisffuxpgpvspofafsptjyuisff
xftupofpofgpvsuisffuxpfjhiugpvsuxp
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