A Polynomial-Time Universal Security Amplifier in the Class of Block Ciphers
نویسنده
چکیده
We demonstrate the existence of an eÆcient block cipher with the property that whenever it is composed with any non-perfect cipher, the resulting product is strictly more secure, against an ideal adversary, than the original cipher. We call this property universal security ampli cation, and note that it holds trivially for a one-time pad (a stream cipher). However, as far as we are aware, this is the rst eÆcient block cipher with this property. Several practical implications of this result are considered.
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