For anybody who wants to think about how such entry happened, it seems that the difference among the two presented numbers is in exactly 32 bytes (256 bits):<p><pre><code> 913ff626efddfb f8ae8f1d40da8d13 a90138686884bad1
9db776bb4812f7e3 b2
c37b8cca2eb4ac 1e889d1027bc1ed6 664f3877cd7052c6
db5567a3365cf7e2 c6
</code></pre>
starting from the 162nd byte if I counted correctly, which means the first 5 * 32+1 (or 2 * 80+1) bytes are the same, then 32 bytes differ.<p>(The "easily factorable" number has two bytes which are represented as "bad1" in hex).<p>But thinking about the 256 bits, that's exactly the size of a block on which a typical symmetrical cypher can operate, which suggests some kind of a bug, although the offset of 161 byte is a bit strange.<p>The human would probably just change a few bits to achieve the same effect, not 256, unless he wanted to encode some message, and it doesn't look so. But see also the post of lawnchair_larry here.