Birthday Attack
Birthday attacks are a class of brute-force techniques used in an attempt to solve a class of cryptographic hash functionproblems. These methods take advantage of functions which, when supplied with a random input, return one of 
equallylikely values. By repeatedly evaluating the function for different inputs, the same output is expected to beobtained after about 
evaluations.
References
RSA Laboratories. ``Question 95. What is a Birthday Attack'' and ``Question 96. How Does the Length of a Hash Value Affect Security?'' http://www.rsa.com/rsalabs/faq/.van Oorschot, P. and Wiener, M. ``A Known Plaintext Attack on Two-Key Triple Encryption.'' In Advances in Cryptology--Eurocrypt '90. New York: Springer-Verlag, pp. 366-377, 1991. Yuval, G. ``How to Swindle Rabin.'' Cryptologia 3, 187-189, Jul. 1979.
- Harmonic Divisor Number
- Harmonic Equation
- Harmonic Function
- Harmonic-Geometric Mean
- Harmonic Homology
- Harmonic Logarithm
- Harmonic Map
- Harmonic Mean
- Harmonic Mean Index
- Harmonic Number
- Harmonic Progression
- Harmonic Range
- Harmonic Ratio
- Harmonic Segment
- Harmonic Series
- Harmonic System of Points
- Harmonious Graph
- Harnack's Inequality
- Harnack's Theorems
- Harshad Number
- Hartley Transform
- Hart's Inversor
- Hart's Theorem
- HashLife
- Hasse-Davenport Relation