|THE SECURITY OF THE RSA ENCODING SCHEME RELIES ON THE|
|FACT THAT NOBODY HAS BEEN ABLE TO DISCOVER HOW TO TAKE|
|CUBE ROOTS MOD N WITHOUT KNOWING NS FACTORS|
|UZG MGTJYDUO IW UZG YMA GHTIQDHR MTZGBG YGFDGM IH UZG|
|WATU UZAU HICIQO ZAM CGGH ACFG UI QDMTIXGY ZIP UI UAVG|
|TJCG YIIUM BIQ H PDUZIJU VHIPDHR HM WATUIYM|
Most messages can be decoded by looking for frequently occuring pairs of letters (TH and HE are by far the most common), using these to identify a few letters to begin, and filling in the remaining letters one at a time (``The Gold Bug'' gives a good description, as do many books).
In a known-plaintext situation, the whole code is obtained almost immediately. However, in our example, the letters J, P, and others do not occur in the plaintext, so we could not tell how they are encoded. If we were allowed a chosen plaintext, we would use all the letters to get the entire key.