# Are there examples of encryption in nature?

There are examples of mathematics in nature such as Fibonacci number, fractals, etc. Are there examples of encrypted information?

What I am looking for is a pattern that seems random on the surface, but once you put it through a "decryption" process, it is actually something else. Not patterns that seem random because they are complex.

One example that comes close is DNA. But I see DNA as a form of encoding not encryption.

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You may want to define what you're looking for a bit better. Isn't something that appears random, but is actually a complex formation practically the same as encryption? I don't see the difference between your first and second sentences in your second paragraph. – MCM Feb 20 at 1:58
I see encrypted information as needing to be decrypted before it can make any sense. Whereas given enough resources, complex patterns can be understood without modifying the data itself. For example trying to read an encrypted text vs trying to read Chinese (if you don't know Chinese). – Karn Ratana Feb 20 at 2:24
@KarnRatana: encryption implies the concept of "secrecy". You encrypt data so that only a certain individual or group of individuals can access it using a certain key. See also stackoverflow.com/questions/4657416/… . It is difficult to imagine a biological situation where secrecy would be an issue. – nico Feb 20 at 10:17
@nico Thank you. I am not looking for encoding but encryption. Which, as you mentioned, does imply secrecy. I'm not well versed in biology and couldn't think of any example, hence the question =) – Karn Ratana Feb 20 at 13:03

One example is in the development of the immune system. V(D)J recombination, antibody production, and T-cell receptor production generates a specific "key" that, in most cases, can only be bypassed by that individual's molecular inventory.

In that sense, parasites, mutualists, and commensalists could be viewed as black, white, and grey hat hackers, respectively.

Another example is the organism-specific tRNA synthase inventory and the matching tRNAs.

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 This sounds similar to what @Nick mentioned (in concept not biology). Which deals more with authentication than protecting a "message". – Karn Ratana Feb 21 at 17:58

Perhaps protein folding is an example of decryption? From a single primary sequence (i.e. the string of amino acids), it is impossible to guess the function of a protein. The folded protein is the functional unit (of course it might be further modified).

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 Encryption is not about the impossibility of deciphering, that would rather be hashing. Also note that knowing folding does not immediately give you the function, just the structure. – nico Feb 20 at 10:53

I would think that the Bacteria - Phage restriction enzyme and methylation enzyme race could be thought of as a form of encryption. If your DNA isn't "signed" with the appropriate methylation patterns then it gets chopped into pieces and destroyed. This is the signing/verifying side of encryption rather then the encrypt/decrypt side, however.

http://en.wikipedia.org/wiki/Restriction_modification_system

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 This sounds similar to what @nbogard mentioned (in concept not biology). Which deals more with authentication than protecting a "message". – Karn Ratana Feb 20 at 16:23 R-M systems are fascinating, but it seems to me that there is no message that is encrypted. – Jack Aidley Feb 24 at 22:19 @JackAidley modern encryption is used for signing/verifying messages as much as encrypting/decrypting them. The RM system is a form of signing/verifying. – Nick Feb 25 at 9:28 @Nick: I disagree, my view is closer to that in Wikipedia - "[E]ncryption is the process of encoding messages (or information) in such a way that eavesdroppers or hackers cannot read it, but that authorized parties can". – Jack Aidley Feb 25 at 9:32 @JackAidley Well if you want to be pedantic they can be examples of Cryptography rather than Encryption, but its the closest example in Biology I can think of. – Nick Feb 25 at 9:35

One example is sperm-egg attraction. Many species release their egg and sperm to be joined in water. The egg must try to avoid being fertilized by the sperm of a different species. So an egg secretes a special peptide which attracts the sperm to its location. The amino acid sequence of that peptide is unique for each species and sperm can only recognize the peptide secreted by the egg of their own species. To any other sperm, the peptide is just another molecule present in the water. http://www.ncbi.nlm.nih.gov/books/NBK10010/

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Isn't this just signalling? – Jack Aidley Feb 24 at 22:20
Yes, but isn't encryption a form of signaling? If signaling is communicating biologically, it follows encryption will involve some signaling, but the message will be masked, so that not everyone will understand it. – Drosophila Feb 25 at 13:36
I don't see there's anything masked here; it's just a matter of using different signals. – Jack Aidley Feb 25 at 13:40

Not sure we can name it encryption, but

a pattern that seems random in surface but once you put it through a decryption process, it is actually something else

reminds me about some forms of predatory camouflage. I'm talking from the perspective of the prey: the predator blends with the environment and what the prey perceives is just 'random' environment. When the prey 'decrypts' that there is actually something else, it is generally too late.

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