Christian Schaffner

4-Nonylphenol in Sewage Sludge: Accumulation of Toxic Metabolites from Nonionic Surfactants

Walter Giger, Paul H. Brunner, Christian Schaffner|Science|1984

Cited by 739

Anaerobically treated sewage sludge was found to contain extraordinarily high concentrations of 4-nonylphenol, a metabolite derived from nonionic surfactants of the nonylphenol polyethoxylate type. Concentrations in activated sewage sludge, in mixed primary and secondary sludge, and in aerobically stabilized sludge were substantially lower, suggesting that the formation of 4-nonylphenol is favored under mesophilic anaerobic conditions. Because 4-nonylphenol may be highly toxic to aquatic life, further research is needed on the fate of 4-nonylphenol after sludge is disposed of in the environment.

The Operational Meaning of Min- and Max-Entropy

Robert König, Renato Renner, Christian Schaffner|IEEE Transactions on Information Theory|2009

Cited by 682Open Access

In this paper, we show that the conditional min-entropy H min ( A | B ) of a bipartite state rhoAB is directly related to the maximum achievable overlap with a maximally entangled state if only local actions on the B -part of rhoAB are allowed. In the special case where A is classical, this overlap corresponds to the probability of guessing A given B . In a similar vein, we connect the conditional max-entropy H max ( A | B ) to the maximum fidelity of rhoAB with a product state that is completely mixed on A . In the case where A is classical, this corresponds to the security of A when used as a secret key in the presence of an adversary holding B . Because min- and max-entropies are known to characterize information-processing tasks such as randomness extraction and state merging, our results establish a direct connection between these tasks and basic operational problems. For example, they imply that the (logarithm of the) probability of guessing A given B is a lower bound on the number of uniform secret bits that can be extracted from A relative to an adversary holding B .

Poly cyclic aromatic hydrocarbons in Recent lake sediments—II. Compounds derived from biogenic precursors during early diagenesis

Stuart G. Wakeham, Christian Schaffner, Walter Giger|Geochimica et Cosmochimica Acta|1980

Cited by 675

Random Oracles in a Quantum World

Dan Boneh, Özgür Dagdelen, Marc Fischlin et al.|Lecture notes in computer science|2011

Cited by 435Open Access

Leftover Hashing Against Quantum Side Information

Marco Tomamichel, Christian Schaffner, Adam Smith et al.|IEEE Transactions on Information Theory|2011

Cited by 300Open Access

The Leftover Hash Lemma states that the output of a two-universal hash function applied to an input with sufficiently high entropy is almost uniformly random. In its standard formulation, the lemma refers to a notion of randomness that is (usually implicitly) defined with respect to classical side information. Here, a strictly more general version of the Leftover Hash Lemma that is valid even if side information is represented by the state of a quantum system is shown. Our result applies to almost two-universal families of hash functions. The generalized Leftover Hash Lemma has applications in cryptography, e.g., for key agreement in the presence of an adversary who is not restricted to classical information processing.

Christian Schaffner

Is this you? Claim your profile.

Top publicationsby citations