An abbreviation encryption system that is very powerful. It uses prime numbers in order to make it harder to break. It will convert characters and words into one very large number which is solved using a decryption algorithm.

crypto encryption cryptography
P = 61 <- first prime number (destroy this after computing E and D)
Q = 53 <- second prime number (destroy this after computing E and D)
PQ = 3233 <- modulus (give this to others)
E = 17 <- public exponent (give this to others)
D = 2753 <- private exponent (keep this secret!)

Your public key is (E,PQ).
Your private key is D.

decrypt(C) = (C^D) mod PQ
= (C^2753) mod 3233

encrypt(T) = (T^E) mod PQ
= (T^17) mod 3233
by Spartacus March 19, 2005
RSA is a public key encryption algorithm invented in 1978 by Ron Rivest, Adi Shamir, and Leonard Adleman; and so is named after them.

Text or data is encrypted with one numeric key (or password) and decrypted with another. The person intending to receive the data generates a public and private key. The public key is shared with the sender (and anyone else who may intercept it), and the private key is kept secret with the receiver. Anyone may encrypt data with the public key, but only the private key may decrypt it.
(RSA can be used to secure communication over public channels without ever meeting the person you're speaking with.)
by Raccoon January 6, 2006
omfg that fuckin kilbasa/st.dez smelled like RSA
by Br0nz April 22, 2003
Rub Some Ass; when two people face opposite ways and rub their buttocks together bare ass
Frank and Laird did some RSA the other night.
by Schoff November 22, 2014
Stands for Robot Skeleton Army, the name given by comic Craig Ferguson to fans of his Late Late Show on CBS. Frequently used in hash tags on Twitter.
Twitter hash tag: #rsaoutofcontroltoday
by krisjs1767 November 5, 2011
literally translates to Random Shark Attack.
It is an unnatural occurance that happens when Spock becomes bored and decides to teleport sharks into random places. The sharks are usually engaged in the hunting of their favored prey, the spongebobs. Usually the sharks are safely transported away if no water is immediately available.

Happens most often on Facebook.
Dorris: "So I told her to take that book and shove it up her-"
Tom: "RSA!" -giant shark proceeds to eat Dorris

Carol: via facebook chat "Hiya Susan!"
Susan: "RSA! (^^^)" -and again a shark-
by MVirus May 24, 2010
RSA – Rear Seat Accessory – A member of the opposite gender, usually decorative in nature, that occupies the passenger’s portion of a motorcycle seat.
I’m looking for a new R.S.A.
My biker friend lost his RSA the other day when it fell off; I'm helping him find a new one.
by tall_dave_1959 September 29, 2009