Imagine that you want to send a secret message to your colleague at the CIA. You can ___1___ it to prevent counterspies from reading it. But they'll still know you were sending some sort of message. There's a better option—steganography—which means “___2___.” You tuck your secret away in an unexpected place, like an MP3 or a photo file, to conceal the fact you even shared any information at all.

But you can't hide much in those file types without it being suspiciously large. Executable files, aka applications, on the other hand, come in all sizes—making them an ideal place to ___3___ lots of data. So two computer scientists created an algorithm that packages your encrypted data into an executable file of your choice. Then it ___4___ a new program that works just like the original—except that your secret cargo is inside. The research is in the International Journal of Internet Technology and Secured Transactions. [Rajesh Kumar Tiwari and G. Sahoo, "A Novel Steganographic Methodology for High-Capacity Data Hiding in Executable Files"]

Ideally, this ___5___ would keep your data safe from prying eyes. Until somebody notices that you're sharing an inordinate number of executable files.
【视听版科学小组荣誉出品】
encrypt hidden writing embed spits out handy trick
假设你要给中情局的同事发送一封密函，为了不让间谍窃取情报，你可以给文件加密。但是那些间谍还是会知道你在传送文件。别急，隐写术可以帮上忙。隐写术也就是“文字隐藏”。你可以将秘密文字信息隐藏在MP3或者图片格式文档下，于是你就可以瞒天过海了。 不过，储存太多信息在这种格式下的话，难免会因为体积过大而引人怀疑。而执行文档（又名应用程序）的大小则没有限制，不失为藏秘密的好地方。有两位科学家编写了一个程序，利用它，你可以将秘密信息报存在任意执行文档下，而原有程序照常运行——只是还隐藏了你的秘密。这项研究成果刊登在《网络技术与安全交易》国际期刊上。 理想状态下，这种小把戏可以让你的信息数据不被人偷窥，当然你要是分享太多执行文档的话可就要引起别人的怀疑了。