æå·è§£èªã®å æ¬çãªæ¢æ±ãæå·è§£èªã®æŽå²çã»çŸä»£çææ³ãæå·æè¡ã®é²åãæ å ±ã»ãã¥ãªãã£ãžã®åœ±é¿ã
è§£èªïŒæå·è§£èªè¡ã®èžè¡ãè§£ãæãã
æ å ±ã»ãã¥ãªãã£ã®é åã§ã¯ãæå·æè¡ãšæå·è§£èªã¯ãåµé ãšç Žå£ã®çµ¶ãéãªããã³ã¹ã®äžã«ååšããŸããæå·æè¡ãæå·åã«ããå®å šãªéä¿¡æ¹æ³ã®èšèšã«çŠç¹ãåœãŠãã®ã«å¯Ÿããæå·è§£èªã¯ãããã®æ¹æ³ãç Žããé ãããå¹³æãæããã«ããããã«åªåããŸãããã®ããã°æçš¿ã§ã¯ãæå·è§£èªã®é åçãªäžçãæãäžãããã®æŽå²çã«ãŒããçŸä»£çãªææ³ããããŠé²è¡äžã®é²åãæ¢ããŸãã
æå·è§£èªã®æŽå²çåºç€
æå·è§£èªã¯çŸä»£ã®çºæã§ã¯ãããŸããããã®æŽå²ã¯äœå幎ã«ãåã³ãŸããåæã®äŸã¯å€ä»£ææã«èŠãããããã§ã¯è»äºããã³å€äº€ç®çã§ç§å¯ã®çèšã䜿çšãããŠããŸããããããã®ã¡ãã»ãŒãžãè§£èªããå¿ èŠæ§ã¯ãèªç¶ãšæå·è§£èªæè¡ã®éçºã«ã€ãªãããŸããã
åæã®äŸãšææ³
- å€ä»£ãšãžããïŒéæšæºçãªããšãã°ãªããé èœã®ããã«äœ¿çšãããŠãããšãã蚌æ ããããããã¯æå·åã®åæ©çãªåœ¢æ ã§ãã
- å€ä»£ã®ãªã·ã£ïŒã¹ãã«ã¿ã®ã¹ã³ã€ã¿ã¬ãŒã¯ã転眮æå·ã§ãããã¡ãã»ãŒãžãèªãã«ã¯ç¹å®ã®æ£ã®çŽåŸãå¿ èŠã§ããã
- ã¢ã«ïŒãã³ãã£ãŒïŒ9äžçŽïŒïŒã¢ã©ãã¢ã®ååŠè ã¢ã«ïŒãã³ãã£ãŒã¯ãå€å žçãªæå·ãè§£èªããããã®ç»æçãªææ³ã§ããé »åºŠåæãéçºãããšãããŠããŸãã圌ã¯ãäžããããããã¹ãã§ã¯ãç¹å®ã®æåãä»ã®æåãããé »ç¹ã«çŸããããšã芳å¯ããŸãããæå·æã®èšå·ã®é »åºŠãåæããããšã«ããã察å¿ããå¹³æã®æåãæšæž¬ããããšãã§ããŸããããã®ææ³ã¯ãã·ãŒã¶ãŒæå·ã®ãããªåäžã¢ã«ãã¡ããã眮ææå·ã«å¯ŸããŠç¹ã«å¹æçã§ããã
ã«ããµã³ã¹ãšå€è¡šåæå·ã®å°é
ã«ããµã³ã¹æã«ã¯å€äº€æžç°¡ãæ¥å¢ããããæŽç·Žãããæå·åæ¹æ³ãå¿ èŠãšãªããŸããããŽã£ãžã¥ãã«æå·ã®ãããªå€è¡šåæå·ã¯ãåäžã¢ã«ãã¡ãããæå·ã®è匱æ§ã«å¯ŸåŠããããã«ç»å ŽããŸããããŽã£ãžã¥ãã«æå·ã¯ãããŒã¯ãŒãã䜿çšããŠå¹³æã®æåãã·ããããé »åºŠåæãããå°é£ã«ããŸãããããããæå·è§£èªè ãæçµçã«ãããã®æå·ãè§£èªããææ³ãéçºããŸãããç¹ã«ããŒã¯ãŒãã®é·ããç¹å®ããããšã«ãã£ãŠã§ãã
çŸä»£ã®æå·è§£èªïŒããžã¿ã«æŠå Ž
ã³ã³ãã¥ãŒã¿ã®åºçŸã¯ãæå·æè¡ãšæå·è§£èªã®äž¡æ¹ã«é©åœããããããŸãããçŸä»£ã®æå·åã¢ã«ãŽãªãºã ã¯ãå€å žçãªãã®ãããã¯ããã«è€éã§ãããæ°åŠçåçãšèšç®èœåãå©çšããŠé«ã¬ãã«ã®ã»ãã¥ãªãã£ãéæããŠããŸãããã®çµæãçŸä»£ã®æå·è§£èªã¯ãé«åºŠãªæ°åŠçææ³ãšèšç®ãªãœãŒã¹ã«å€§ããäŸåããŠããŸãã
äžè¬çãªæå·è§£èªææ³
- ç·åœããæ»æïŒãã®çŽæ¥çãªã¢ãããŒãã¯ãæ£ããéµãèŠã€ãããŸã§ãèãããããã¹ãŠã®éµã詊ãããšã§ããç·åœããæ»æã®æå¹æ§ã¯ãéµã®é·ããšå©çšå¯èœãªèšç®èœåã«äŸåããŸããéµãé·ãã»ã©ãæå·ãè§£èªããããã«å¿ èŠãªæéã¯ææ°é¢æ°çã«å¢å ããŸãã
- é »åºŠåæïŒå蚪ïŒïŒçŸä»£ã®æå·ã«å¯ŸããŠã¯å¹æãèããã®ã®ãé »åºŠåæã¯ãç¹ã«åçŽåãããããŸãã¯äžé©åã«å®è£ ãããæå·ãæ±ãå Žåã«ãäŸç¶ãšããŠè²ŽéãªæããããæäŸã§ããŸããããæŽç·Žãããçµ±èšåæææ³ã䜿çšãããŠããŸãã
- å·®åè§£èªïŒEli BihamãšAdi Shamirã«ãã£ãŠéçºããããã®ææ³ã¯ãæå·ãžã®å ¥åã®éããçµæã®åºåã«ã©ã®ããã«åœ±é¿ãããã調ã¹ãŸãããããã®éããåæããããšã«ãããæå·è§£èªè ã¯éµã«é¢ããæ å ±ãåŸãããšãã§ããŸãã
- ç·åœ¢è§£èªïŒMitsuru Matsuiã«ãã£ãŠå°å ¥ãããç·åœ¢è§£èªã¯ãæå·ã®æäœã«å¯Ÿããç·åœ¢è¿äŒŒãèŠã€ããããšããŸãããããã®è¿äŒŒã¯ãéµããããå埩ããããã«äœ¿çšã§ããŸãã
- ãµã€ããã£ãã«æ»æïŒãããã®æ»æã¯ãã¢ã«ãŽãªãºã èªäœãçŽæ¥æ»æããã®ã§ã¯ãªããæå·ã·ã¹ãã ã®ç©ççãªå®è£ ãæªçšããŸãããµã€ããã£ãã«æ»æã¯ãã¿ã€ãã³ã°ã®å€åãé»åæ¶è²»ãé»ç£æŸå°ãããã«ã¯é³é¿æŸåºã枬å®ããŠãç§å¯æ å ±ãæœåºããããšãã§ããŸãã
- éžæå¹³ææ»æïŒãã®ã·ããªãªã§ã¯ãæå·è§£èªè ã¯ä»»æã®å¹³æãéžæãã察å¿ããæå·æãååŸã§ããŸããããã«ãããæå·ã®åäœãåæããéµãæšæž¬ã§ããå¯èœæ§ããããŸãã
- æ¢ç¥å¹³ææ»æïŒæå·è§£èªè ã¯ãããã€ãã®ã¡ãã»ãŒãžã®å¹³æãšå¯Ÿå¿ããæå·æã®äž¡æ¹ã«ã¢ã¯ã»ã¹ã§ããŸãããã®æ å ±ã¯ãéµãæšæž¬ããããä»ã®æå·æãè§£èªãããããããã«äœ¿çšã§ããŸãã
ã«ãŒã¯ããã¹ã®åçïŒçŸä»£æå·ã®åºç€
æå·æè¡ã«ãããåºæ¬çãªåçã§ããã«ãŒã¯ããã¹ã®åçã¯ãéµä»¥å€ã®ãã¹ãŠãå ¬ç¥ã§ãã£ãŠããæå·ã·ã¹ãã ã¯å®å šã§ããã¹ãã ãšè¿°ã¹ãŠããŸãããã®åçã¯ãéµã®ç§å¯æ§ãšã¢ã«ãŽãªãºã ã®å ç¢æ§ã®éèŠæ§ã匷調ããŠããŸããçŸä»£ã®æå·è§£èªè ã¯ãæ»æè ãã¢ã«ãŽãªãºã ãç¥ã£ãŠãããšä»®å®ããéµç®¡çãå®è£ ã®è匱æ§ãæªçšããããšã«çŠç¹ãåœãŠãããšããããããŸãã
æå·æè¡ãšæå·è§£èªã®é²åïŒçµ¶ãéãªãè»æ¡ç«¶äº
æå·æè¡ãšæå·è§£èªã¯ãç¶ç¶çãªè»æ¡ç«¶äºã«åŸäºããŠããŸããæ°ããæå·åã¢ã«ãŽãªãºã ãéçºãããã«ã€ããŠãæå·è§£èªè ã¯ããããç Žãæ°ããææ³ãèæ¡ããŸãããã®ç¶ç¶çãªãµã€ã¯ã«ã¯ãäž¡åéã®ã€ãããŒã·ã§ã³ãæšé²ããæ å ±ãä¿è·ããããã®ããæŽç·Žãããææ³ã«ã€ãªãããŸãã
æå·æè¡ã®ãã¬ãŒã¯ã¹ã«ãŒãšãã®åŸã®è§£èªã®äŸ
- DESïŒData Encryption StandardïŒïŒãã€ãŠåºã䜿çšãããŠããå ±ééµã¢ã«ãŽãªãºã ã§ããããæ¯èŒççãéµé·ïŒ56ãããïŒã®ããã«æçµçã«ç ŽãããŸãããèšç®èœåã®åäžã«ãããç·åœããæ»æãå®çŸå¯èœã«ãªããŸããã
- MD5ïŒMessage Digest 5ïŒïŒåºã䜿çšãããŠããããã·ã¥é¢æ°ã§ããMD5ã¯ãè¡çªïŒ2ã€ã®ç°ãªãå ¥åãåãããã·ã¥å€ãçããïŒã®äœæãå¯èœã«ããè匱æ§ãããããšã倿ããŸãããããã«ããã匷åãªè¡çªèæ§ãå¿ èŠãšããã¢ããªã±ãŒã·ã§ã³ã«ã¯äžåãã«ãªããŸããã
- SHA-1ïŒSecure Hash Algorithm 1ïŒïŒMD5ãšåæ§ã«ãSHA-1ãè¡çªæ»æã«å¯ŸããŠè匱ã§ããããšã倿ããŸãããMD5ãããèæ§ããããŸããããæçµçã«ã¯SHA-2ãšSHA-3ã«åã£ãŠä»£ããããŸããã
æšæºãšã³ã³ããã£ã·ã§ã³ã®åœ¹å²
AESïŒAdvanced Encryption StandardïŒã®ãããªæå·æšæºã¯ãéä¿¡ãšããŒã¿ã¹ãã¬ãŒãžã®ã»ãã¥ãªãã£ã確ä¿ããäžã§éèŠãªåœ¹å²ãæãããŠããŸããAESã¯ãç±³åœåœç«æšæºæè¡ç ç©¶æïŒNISTïŒãäž»å¬ããå ¬éã³ã³ããã£ã·ã§ã³ãéããŠéžã°ããŸããããã®ãªãŒãã³ãªããã»ã¹ã«ãããäžçäžã®æå·æè¡è ãã¢ã«ãŽãªãºã ã粟æ»ãããã¹ãããããšãã§ãããã®ã»ãã¥ãªãã£ãžã®ä¿¡é Œãé«ãŸããŸãããNISTã®ããã·ã¥é¢æ°ã³ã³ããã£ã·ã§ã³ã®ãããªã³ã³ããã£ã·ã§ã³ããæ°ããæ¹è¯ãããæå·ã¢ã«ãŽãªãºã ã®éçºã«ã€ãªãããŸããã
éåè§£èªïŒå€å žçæå·ãžã®è åš
éåã³ã³ãã¥ãŒãã£ã³ã°ã®åºçŸã¯ãåºã䜿çšãããŠããå€ãã®æå·åã¢ã«ãŽãªãºã ã«é倧ãªè åšããããããŠããŸããéåååŠã®åçã«åºã¥ããéåã³ã³ãã¥ãŒã¿ã¯ãäžéšã®èšç®ãå€å žçãªã³ã³ãã¥ãŒã¿ãããã¯ããã«éãå®è¡ããå¯èœæ§ããããŸããããšãã°ãShorã®ã¢ã«ãŽãªãºã ã¯å€§ããªæ°ãå¹ççã«å æ°åè§£ã§ããããã¯RSAããã³ãã®ä»ã®å ¬é鵿å·ã·ã¹ãã ã®ã»ãã¥ãªãã£ã®åºç€ãšãªã£ãŠããŸãã
Shorã®ã¢ã«ãŽãªãºã ãšãã®åœ±é¿
Peter Shorã«ãã£ãŠéçºãããShorã®ã¢ã«ãŽãªãºã ã¯ãæ¢ç¥ã®æè¯ã®å€å žçã¢ã«ãŽãªãºã ãããææ°é¢æ°çã«éã倧ããªæ°ãå æ°åè§£ã§ããéåã¢ã«ãŽãªãºã ã§ããããã¯ã倧ããªæ°ã®å æ°åè§£ã®å°é£ãã«äŸåããRSAæå·ã·ã¹ãã ã«çŽæ¥çãªè åšããããããŸããå€§èŠæš¡ãªéåã³ã³ãã¥ãŒã¿ãçŸå®ã®ãã®ãšãªãã°ãRSAããã³åæ§ã®ã¢ã«ãŽãªãºã ã¯è匱ã«ãªããŸãã
ãã¹ãéåæå·ïŒéåæä»£ãžã®æºå
éåã³ã³ãã¥ãŒã¿ããã®è åšã«å¯ŸåŠãããããç ç©¶è ã¯ãã¹ãéåæå·ïŒéåèæ§æå·ãšãåŒã°ããŸãïŒãéçºããŠããŸãããã¹ãéåæå·ã¯ãå€å žçããã³éåã®äž¡æ¹ã®ã³ã³ãã¥ãŒã¿ããã®æ»æã«èæ§ã®ããæå·ã¢ã«ãŽãªãºã ãäœæããããšãç®çãšããŠããŸãããããã®ã¢ã«ãŽãªãºã ã¯éåžžãäž¡æ¹ã®ã¿ã€ãã®ã³ã³ãã¥ãŒã¿ã«ãšã£ãŠå°é£ã§ãããšèããããŠããæ°åŠçåé¡ã«åºã¥ããŠããŸãã
ãã¹ãéåæå·ã¢ã«ãŽãªãºã ã®äŸ
- æ ŒåããŒã¹æå·ïŒé«æ¬¡å 空éã®æ Œåã«é¢é£ããåé¡ã®é£ããã«åºã¥ããŠããŸãã
- ã³ãŒãããŒã¹æå·ïŒäžè¬çãªç·åœ¢ã³ãŒãã®ãã³ãŒãã®å°é£ãã«åºã¥ããŠããŸãã
- å€é åŒæå·ïŒå€é åŒæ¹çšåŒã®é£ç«æ¹çšåŒãè§£ãããšã®å°é£ãã«åºã¥ããŠããŸãã
- ããã·ã¥ããŒã¹æå·ïŒæå·ããã·ã¥é¢æ°ã®ã»ãã¥ãªãã£ã«åºã¥ããŠããŸãã
NISTã¯çŸåšãåºç¯ãªæ¡çšã®ããã®ãã¹ãéåæå·ã¢ã«ãŽãªãºã ãéžæããããã®æšæºåããã»ã¹ã宿œããŠããŸãããã®ããã»ã¹ã«ã¯ãææ¡ãããã¢ã«ãŽãªãºã ã®ã»ãã¥ãªãã£ãšããã©ãŒãã³ã¹ã確ä¿ããããã®å³æ Œãªè©äŸ¡ãšãã¹ããå«ãŸããŸãã
æå·è§£èªã«ãããå«ççèæ ®äºé
æå·è§£èªã¯ããããã匷åãªããŒã«ãšåæ§ã«ãåãšæªã®äž¡æ¹ã«äœ¿çšã§ããŸããæå·ã·ã¹ãã ã®è匱æ§ãç¹å®ããããšã«ããæ å ±ã»ãã¥ãªãã£ãä¿è·ããäžã§éèŠãªåœ¹å²ãæãããŸãããã¹ãã€æŽ»åãäžæ£ãªããŒã¿ã¢ã¯ã»ã¹ãªã©ãæªæã®ããç®çã«ã䜿çšã§ããŸãã
æå·è§£èªã®ãã¥ã¢ã«ãŠãŒã¹æ§è³ª
åæ³çãªç®çã§æå·ãè§£èªããããã«äœ¿çšãããã®ãšåãææ³ã¯ãéæ³ãªæŽ»åã«ã䜿çšã§ããŸãããããã£ãŠãæå·è§£èªè ãå«çååãšæ³çèŠå¶ãéµå®ããããšã¯éåžžã«éèŠã§ãã責任ããæå·è§£èªè ã¯ãå人çãªå©çã®ããã«è匱æ§ãæªçšããããä»è ã害ãããããã®ã§ã¯ãªããã»ãã¥ãªãã£ãåäžããããã©ã€ãã·ãŒãä¿è·ããããã«ã¹ãã«ã䜿çšããŸãã
éææ§ãšé瀺ã®éèŠæ§
æå·ã·ã¹ãã ã§è匱æ§ãçºèŠãããå Žåããããã®ã·ã¹ãã ã®éçºè ãšãŠãŒã¶ãŒã«è²¬ä»»ãæã£ãŠé瀺ããããšãéèŠã§ããããã«ããããªã¹ã¯ã軜æžããããã®æ¯æ£æªçœ®ãè¬ããããšãã§ããŸãããã ããä¿®æ£ãããåã«æ»æè ã«è匱æ§ãæªçšããæ©äŒãäžããªãããã«ãé瀺ããã»ã¹ã¯æ éã«ç®¡çããå¿ èŠããããŸãã
çµè«ïŒæå·è§£èªã®æ°žç¶çãªéèŠæ§
æå·è§£èªã¯ãããžã¿ã«æä»£ã«ãããæ å ±ã®ã»ãã¥ãªãã£ã確ä¿ããäžã§æ¥µããŠéèŠãªåœ¹å²ãæãããäžå¯æ¬ ãªåéã§ããæå·ã·ã¹ãã ã«çµ¶ããææŠãããã¹ãããããšã«ãããæå·è§£èªè ã¯è匱æ§ãç¹å®ããæå·æè¡ã®ã€ãããŒã·ã§ã³ãæšé²ããã®ã«åœ¹ç«ã¡ãŸãããã¯ãããžãŒãé²åãç¶ããã«ã€ããŠãæå·è§£èªã¯å ç¢ãªæ å ±ã»ãã¥ãªãã£ãšã³ã·ã¹ãã ã®äžå¯æ¬ ãªã³ã³ããŒãã³ãã§ããç¶ããã§ããããæå·æè¡è ãšæå·è§£èªè ã®éã®ç¶ç¶çãªæŠãã¯ãå®å šãªéä¿¡ãšããŒã¿ä¿è·ã®æªæ¥ã圢äœãç¶ããã§ããããéåã³ã³ãã¥ãŒãã£ã³ã°ã®å°é ã¯ãæ°ããªè åšã«çŽé¢ããŠããŒã¿ã»ãã¥ãªãã£ãç¶æããããã«ããã¹ãéåæå·ãžã®ç©æ¥µçãªã¢ãããŒããå¿ èŠãšããŸããæçµçã«ãå«ççèæ ®äºé ã¯ã瀟äŒã®å©çã®ããã«æå·è§£èªã䜿çšãããããšãä¿èšŒããããã«ããã®é©çšãå°ãå¿ èŠããããŸãã
ããªããåŠçããµã€ããŒã»ãã¥ãªãã£ã®å°éå®¶ããŸãã¯åã«æå·ã®å éšæ§é ã«èå³ããã人ã§ãã£ãŠããæå·è§£èªãçè§£ããããšã¯ãæ å ±ã»ãã¥ãªãã£ã®è€éãªç¶æ³ãããã²ãŒãããããã«äžå¯æ¬ ã§ããæå·ãè§£èªããããšã«é¢ãã課é¡ãšææ³ãçè§£ããããšã«ããã匷åãªæå·ã®éèŠæ§ãšãããžã¿ã«è³ç£ãä¿è·ããããã®ç¶ç¶çãªèŠæã®å¿ èŠæ§ãããããçè§£ã§ããŸãã