题目：
We found this very mysterious image, it doesn't look complete and there seems to be something hidden on it... does this mean anything to you? beach.jpg This flag is not in the standard flag format. The flag contains digits and no special characters, convert the message to lowercase and then add IceCTF{message} to it. 10331c4d
用谷歌搜索一下，发现是本书
然后我们得到信息（用记事本打开即可）：
58-7-9意思就是第58页，第七行，第九个单词
58-7-9
210-13-2
67-3-16
85-17-15
305-18-4
83-12-18
75-8-15
47-4-2
83-20-11
208-6-6
85-11-6
75-7-3
106-9-14
然后得到：
58-7-9 not
210-13-2 0s
67-3-16 one
85-17-15 becomes
305-18-4 zero
83-12-18 routed
75-8-15 3
47-4-2 authenticity
83-20-11 David
208-6-6 be
85-11-6 of
75-7-3 0
106-9-14 x
得到flag
IceCTF{n0obzr3adbo0x}
原文链接：
https://0x90r00t.com/2016/08/26/icectf-2016-crypto-140-sand-castle-write-up/
本文转自 天道酬勤VIP 51CTO博客，原文链接:http://blog.51cto.com/tdcqvip/1941818
