### Abstract

The following coding problem for correlated discrete memoryless sources is considered. The two sources can be separately block encoded, and the values of the encoding functions are available to a decoder who wants to answer a certain question concerning the source outputs. Typically, this question has only a few possible answers (even as few as two). The rates of the encoding functions must be found that enable the decoder to answer this question correctly with high probability. It is proven that these rates are often as large as those needed for a full reproduction of the outputs of both sources. Furthermore, if one source is completely known at the decoder, this phenomenon already occurs when what is asked for is the joint type (joint composition) of the two source output blocks, or some function thereof such as the Hamming distance of the two blocks or (for alphabet size at least three) just the parity of this Hamming distance.

Original language | English |
---|---|

Pages (from-to) | 398-408 |

Number of pages | 11 |

Journal | IEEE Transactions on Information Theory |

Volume | 27 |

Issue number | 4 |

DOIs | |

Publication status | Published - 1981 |

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### ASJC Scopus subject areas

- Computer Science Applications
- Information Systems
- Library and Information Sciences
- Electrical and Electronic Engineering

### Cite this

*IEEE Transactions on Information Theory*,

*27*(4), 398-408. https://doi.org/10.1109/TIT.1981.1056381

**To Get a Bit of Information May Be As Hard As to Get Full Information.** / Ahlswede, Rudolf; Csiszár, I.

Research output: Contribution to journal › Article

*IEEE Transactions on Information Theory*, vol. 27, no. 4, pp. 398-408. https://doi.org/10.1109/TIT.1981.1056381

}

TY - JOUR

T1 - To Get a Bit of Information May Be As Hard As to Get Full Information

AU - Ahlswede, Rudolf

AU - Csiszár, I.

PY - 1981

Y1 - 1981

N2 - The following coding problem for correlated discrete memoryless sources is considered. The two sources can be separately block encoded, and the values of the encoding functions are available to a decoder who wants to answer a certain question concerning the source outputs. Typically, this question has only a few possible answers (even as few as two). The rates of the encoding functions must be found that enable the decoder to answer this question correctly with high probability. It is proven that these rates are often as large as those needed for a full reproduction of the outputs of both sources. Furthermore, if one source is completely known at the decoder, this phenomenon already occurs when what is asked for is the joint type (joint composition) of the two source output blocks, or some function thereof such as the Hamming distance of the two blocks or (for alphabet size at least three) just the parity of this Hamming distance.

AB - The following coding problem for correlated discrete memoryless sources is considered. The two sources can be separately block encoded, and the values of the encoding functions are available to a decoder who wants to answer a certain question concerning the source outputs. Typically, this question has only a few possible answers (even as few as two). The rates of the encoding functions must be found that enable the decoder to answer this question correctly with high probability. It is proven that these rates are often as large as those needed for a full reproduction of the outputs of both sources. Furthermore, if one source is completely known at the decoder, this phenomenon already occurs when what is asked for is the joint type (joint composition) of the two source output blocks, or some function thereof such as the Hamming distance of the two blocks or (for alphabet size at least three) just the parity of this Hamming distance.

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UR - http://www.scopus.com/inward/citedby.url?scp=0019584491&partnerID=8YFLogxK

U2 - 10.1109/TIT.1981.1056381

DO - 10.1109/TIT.1981.1056381

M3 - Article

VL - 27

SP - 398

EP - 408

JO - IEEE Transactions on Information Theory

JF - IEEE Transactions on Information Theory

SN - 0018-9448

IS - 4

ER -