Bitcoin defcon warning

The client will gain nothing by repeating the request without modifications. Jump to navigation Jump to bitcoin defcon warning For the process of writing in shorthand, see Stenography.

The same image viewed by white, blue, green and red lights reveals different hidden numbers. The first recorded use of the term was in 1499 by Johannes Trithemius in his Steganographia, a treatise on cryptography and steganography, disguised as a book on magic. The advantage of steganography over cryptography alone is that the intended secret message does not attract attention to itself as an object of scrutiny. Plainly visible encrypted messages, no matter how unbreakable they are, arouse interest and may in themselves be incriminating in countries in which encryption is illegal. Whereas cryptography is the practice of protecting the contents of a message alone, steganography is concerned with concealing the fact that a secret message is being sent as well as concealing the contents of the message. Steganography includes the concealment of information within computer files.

In digital steganography, electronic communications may include steganographic coding inside of a transport layer, such as a document file, image file, program or protocol. Media files are ideal for steganographic transmission because of their large size. The first recorded uses of steganography can be traced back to 440 BC when Herodotus mentions two examples in his Histories. In his work Polygraphiae Johannes Trithemius developed his so-called “Ave-Maria-Cipher” that can hide information in a Latin praise of God. Steganography has been widely used for centuries. Hidden messages within a wax tablet: in ancient Greece, people wrote messages on wood and covered it with wax that bore an innocent covering message.

Hidden messages on messenger’s body were also used in ancient Greece. Herodotus tells the story of a message tattooed on the shaved head of a slave of Histiaeus, hidden by the hair that afterwards grew over it, and exposed by shaving the head. The message allegedly carried a warning to Greece about Persian invasion plans. Messages written in Morse code on yarn and then knitted into a piece of clothing worn by a courier. Messages written on envelopes in the area covered by postage stamps. In the early days of the printing press, it was common to mix different typefaces on a printed page because the printer did not have enough copies of some letters in one typeface. Thus, a message could be hidden by using two or more different typefaces, such as normal or italic.