0000000000020793

AUTHOR

Jörg Rothe

showing 3 related works from this author

X-ray absorption spectroscopic study of trivalent and tetravalent actinides in solution at varying pH values

2009

Abstract We perform X-ray absorption spectroscopy (XAS) investigations to monitor the stabilization of redox sensitive trivalent and tetravalent actinide ions in solution at acidic conditions in a pH range from 0 to 3 after treatment with holding reductants, hydroxylamine hydrochloride (NH2OHHCl) and Rongalite (sodium hydroxymethanesulfinate, CH3NaO3S). X-ray absorption near edge structure (XANES) measurements clearly demonstrate the stability of the actinide species for several hours under the given experimental conditions. Hence, structural parameters can be accurately derived by extended X-ray absorption fine structure (EXAFS) investigations. The coordination structure of oxygen atoms be…

RongaliteX-ray absorption spectroscopychemistry.chemical_compoundAbsorption spectroscopyExtended X-ray absorption fine structureChemistryMetal ions in aqueous solutionInorganic chemistryActinidePhysical and Theoretical ChemistryAbsorption (chemistry)XANESRadiochimica Acta
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If P≠NP then some strongly noninvertible functions are invertible

2006

AbstractRabi, Rivest, and Sherman alter the standard notion of noninvertibility to a new notion they call strong noninvertibility, and show—via explicit cryptographic protocols for secret-key agreement (Rabi and Sherman attribute this protocol to Rivest and Sherman) and digital signatures (Rabi and Sherman)—that strongly noninvertible functions are very useful components in protocol design. Their definition of strong noninvertibility has a small twist (“respecting the argument given”) that is needed to ensure cryptographic usefulness. In this paper, we show that this small twist has a consequence: unless P=NP, some strongly noninvertible functions are invertible.

Discrete mathematicsGeneral Computer ScienceComputational complexity theorybusiness.industryP versus NP problemOne-way functionsCryptographyOne-way functionCryptographic protocolTheoretical Computer Sciencelaw.inventionComputational complexityInvertible matrixDigital signaturelawAssociativityCryptographyStrong noninvertibilitybusinessAssociative propertyMathematicsTheoretical Computer Science
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If P ≠ NP then Some Strongly Noninvertible Functions Are Invertible

2001

Rabi, Rivest, and Sherman alter the standard notion of noninvertibility to a new notion they call strong noninvertibility, and show--via explicit cryptographic protocols for secret-key agreement ([RS93, RS97] attribute this to Rivest and Sherman) and digital signatures [RS93, RS97]--that strongly noninvertible functions would be very useful components in protocol design. Their definition of strong noninvertibility has a small twist ("respecting the argument given") that is needed to ensure cryptographic usefulness. In this paper, we show that this small twist has a large, unexpected consequence: Unless P = NP, some strongly noninvertible functions are invertible.

Discrete mathematicsComputational complexity theorybusiness.industryP versus NP problemCryptographyCryptographic protocollaw.inventionInvertible matrixDigital signaturelawTwistbusinessTime complexityMathematics
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