Before public key cryptosystem is devised, it was devised in 1976, Whitfield Diffie and Martin E. by Hellman, using the channel which is not safe, the secret key safely sending and receiving key exchange system in order to do.

It was problem whether with secret key code, the key information which both of decoding encoding and the cryptogram is used different from open key code, it is necessary for both parties of the transmission person and the receiving believer to share, how does this secret key and gives to the partner safely that.

With Diffie-Hellman key exchange, making use of discrete logarithm problem, it is not the secret key itself, information of the release which is formed from random number and secret key sending and receiving is done.

Like this, by the fact that it does, communication contents being wiretapped by the third party, there are no times when at once it is known the secret key, can exchange key information safely. However, interrupting the communication of the transmission person and the receiving believer, the [ri] which designate the information of release as your own ones being able to apply, you try the cryptanalysis, vis-a-vis “intermediate person attack” weak thing is known.

digg <Dig>

Reading: Dig
Field:
WWW > Sight > community > digg

The participation type news sight which publishes the information which Kevin Rose began in 2004 December, are contributed from the reader. As for the user it can contribute the link to the news which by its finds by registering freely. This the behavior which is contributed is called “digg”.

If you register, it can vote in the news which you feel, that it is funny, contribute the comment for news. In addition, negative vote (bury) it is possible also vis-a-vis contribution and the contribution of advertisement object which do not like to do. The news where the number of polls reaches to one constant is indicated in the place where the top page of digg is conspicuous up to 15.

Time before digg establishes from, with the participation type technology type news sight Slashdot which is, it chooses the news which the editor should publish, after compiling, it publishes. Vis-a-vis this, if with digg the register user anyone can contribute news. Also the point that is the major feature of digg it decides the value of news user itself with poll. In addition you can say that from the fact that you can contribute the general user freely, it is the news sight whose necessity to report speedily is very high.

Digital Hi-Vision <Digital hi-vision>

Field:
Multimedia > broadcast > Digital Hi-Vision

The hi-vision broadcast which is done with the BS digital broadcast which is started in 2000.

SDTV (until recently similar standard picture quality broadcast) with HDTV (high picture quality hi-vision broadcast) both the time zone can coexist with BS digital broadcast separately in the identical channel, but latter thing is called digital hi-vision broadcast.

Digital hi-vision broadcast with the broadcast type which digitalizes the hi-vision broadcast which is started from 1989, after using sound and the image format which are similar to hi-vision broadcast, MPEG-2 AAC (MPEG-2 Advanced Audio Coding) has used for MPEG-2 Video and speech compression for image compression.

Digital Linear Tape <DLTtape>

Alias:
DLT
Field:
Storage > magnetic tape > Digital Linear Tape