{"id":33406,"date":"2023-12-08T02:29:26","date_gmt":"2023-12-08T02:29:26","guid":{"rendered":"https:\/\/masterskills.org\/blog\/ma-hoa-khoa-bi-mat-private-key-la-gi.html"},"modified":"2023-12-23T11:28:45","modified_gmt":"2023-12-23T04:28:45","slug":"ma-hoa-khoa-bi-mat-private-key-la-gi","status":"publish","type":"post","link":"https:\/\/masterskills.org\/blog\/ma-hoa-khoa-bi-mat-private-key-la-gi.html","title":{"rendered":"M\u00e3 h\u00f3a kh\u00f3a b\u00ed m\u1eadt (Private key) l\u00e0 g\u00ec?"},"content":{"rendered":"
\n
\n
<\/div>\n
\n

H\u00ecnh minh h\u1ecda (Ngu\u1ed3n: notebookbft)<\/p>\n<\/div>\n<\/div>\n

M\u00e3 h\u00f3a kh\u00f3a b\u00ed m\u1eadt<\/font><\/h2>\n

Kh\u00e1i ni\u1ec7m<\/b><\/p>\n

M\u00e3 h\u00f3a kh\u00f3a b\u00ed m\u1eadt<\/b> trong ti\u1ebfng Anh g\u1ecdi l\u00e0:\u00a0Private key.<\/b><\/p>\n

M\u00e3 h\u00f3a kh\u00f3a b\u00ed m\u1eadt<\/b>, c\u00f2n g\u1ecdi l\u00e0 m\u00e3 h\u00f3a \u0111\u1ed1i x\u1ee9ng<\/b> hay m\u00e3 h\u00f3a kh\u00f3a ri\u00eang<\/b>, l\u00e0 s\u1eed d\u1ee5ng m\u1ed9t kh\u00f3a cho c\u1ea3 qu\u00e1 tr\u00ecnh m\u00e3 h\u00f3a (\u0111\u01b0\u1ee3c th\u1ef1c hi\u1ec7n b\u1edfi ng\u01b0\u1eddi g\u1eedi th\u00f4ng tin) v\u00e0 qu\u00e1 tr\u00ecnh gi\u1ea3i m\u00e3 (\u0111\u01b0\u1ee3c th\u1ef1c hi\u1ec7n b\u1edfi ng\u01b0\u1eddi nh\u1eadn).\u00a0<\/p>\n

Qu\u00e1 tr\u00ecnh m\u00e3 h\u00f3a kh\u00f3a b\u00ed m\u1eadt \u0111\u01b0\u1ee3c th\u1ef1c hi\u1ec7n nh\u01b0 sau:\u00a0<\/p>\n

M\u1ed9t kh\u00e1ch h\u00e0ng (Anne) mu\u1ed1n g\u1eedi t\u1edbi ng\u01b0\u1eddi b\u00e1n h\u00e0ng (Bob) m\u1ed9t \u0111\u01a1n \u0111\u1eb7t h\u00e0ng, nh\u01b0ng ch\u1ec9 mu\u1ed1n m\u1ed9t m\u00ecnh Bob c\u00f3 th\u1ec3 \u0111\u1ecdc \u0111\u01b0\u1ee3c. Anne m\u00e3 h\u00f3a \u0111\u01a1n \u0111\u1eb7t h\u00e0ng (d\u01b0\u1edbi d\u1ea1ng v\u0103n b\u1ea3n g\u1ed1c) c\u1ee7a m\u00ecnh b\u1eb1ng m\u1ed9t m\u00e3 kh\u00f3a r\u1ed3i g\u1eedi \u0111\u01a1n \u0111\u1eb7t h\u00e0ng \u0111\u00e3 m\u00e3 h\u00f3a \u0111\u00f3 cho Bob.\u00a0<\/p>\n

T\u1ea5t nhi\u00ean, ngo\u00e0i Bob v\u00e0 Anne ra, kh\u00f4ng ai c\u00f3 th\u1ec3 \u0111\u1ecdc \u0111\u01b0\u1ee3c n\u1ed9i dung th\u00f4ng \u0111i\u1ec7p l\u1ed9n x\u1ed9n \u0111\u00e3 m\u00e3 h\u00f3a.<\/p>\n

Khi nh\u1eadn \u0111\u01b0\u1ee3c th\u00f4ng \u0111i\u1ec7p m\u00e3 h\u00f3a, Bob gi\u1ea3i m\u00e3 th\u00f4ng \u0111i\u1ec7p n\u00e0y b\u1eb1ng kh\u00f3a gi\u1ea3i m\u00e3 v\u00e0 \u0111\u1ecdc c\u00e1c th\u00f4ng tin c\u1ee7a \u0111\u01a1n \u0111\u1eb7t h\u00e0ng. \u0110i\u1ec1u \u0111\u00e1ng ch\u00fa \u00fd l\u00e0 trong k\u0129 thu\u1eadt m\u00e3 h\u00f3a kh\u00f3a b\u00ed m\u1eadt, kh\u00f3a \u0111\u1ec3 m\u00e3 h\u00f3a th\u00f4ng \u0111i\u1ec7p v\u00e0 kh\u00f3a \u0111\u1ec3 gi\u1ea3i m\u00e3 th\u00f4ng \u0111i\u1ec7p kh\u00f4ng gi\u1ed1ng nh\u01b0 nhau.\u00a0<\/p>\n

Ng\u01b0\u1eddi g\u1eedi th\u00f4ng \u0111i\u1ec7p s\u1eed d\u1ee5ng m\u1ed9t kh\u00f3a m\u1eadt m\u00e3 \u0111\u1ec3 m\u00e3 h\u00f3a th\u00f4ng \u0111i\u1ec7p v\u00e0 ng\u01b0\u1eddi nh\u1eadn th\u00f4ng \u0111i\u1ec7p c\u0169ng s\u1eed d\u1ee5ng m\u1ed9t kh\u00f3a nh\u01b0 v\u1eady \u0111\u1ec3 \u0111\u1ecdc m\u1eadt m\u00e3 ho\u1eb7c gi\u1ea3i m\u00e3 th\u00f4ng \u0111i\u1ec7p.\u00a0<\/p>\n

K\u0129 thu\u1eadt m\u00e3 h\u00f3a kh\u00f3a b\u00ed m\u1eadt n\u00e0y \u0111\u00e3 \u0111\u01b0\u1ee3c IBM ph\u00e1t tri\u1ec3n, \u00e1p d\u1ee5ng cho c\u00e1c c\u01a1 quan c\u1ee7a Ch\u00ednh Ph\u1ee7 M\u1ef9 n\u0103m 1977 \u0111\u01b0\u1ee3c g\u1ecdi l\u00e0 Ti\u00eau chu\u1ea9n m\u00e3 h\u00f3a d\u1eef li\u1ec7u (DES- data encryption standard).\u00a0<\/p>\n

H\u1ea1n ch\u1ebf c\u1ee7a k\u0129 thu\u1eadt<\/font><\/h3>\n

K\u0129 thu\u1eadt m\u00e3 h\u00f3a kh\u00f3a b\u00ed m\u1eadt l\u00e0 m\u1ed9t ph\u01b0\u01a1ng ph\u00e1p m\u00e3 h\u00f3a th\u00f4ng tin h\u1eefu d\u1ee5ng trong nhi\u1ec1u tr\u01b0\u1eddng h\u1ee3p. Tuy nhi\u00ean, n\u00f3 c\u0169ng c\u00f3 nh\u1eefng h\u1ea1n ch\u1ebf. C\u00e1c b\u00ean tham gia trong qu\u00e1 tr\u00ecnh m\u00e3 h\u00f3a c\u1ea7n ph\u1ea3i tin t\u01b0\u1edfng nhau v\u00e0 ph\u1ea3i ch\u1eafc ch\u1eafn r\u1eb1ng, b\u1ea3n sao c\u1ee7a m\u00e3 h\u00f3a \u0111ang \u0111\u01b0\u1ee3c \u0111\u1ed1i t\u00e1c b\u1ea3o v\u1ec7 c\u1ea9n m\u1eadt.\u00a0<\/p>\n

Th\u00eam v\u00e0o \u0111\u00f3, n\u1ebfu ng\u01b0\u1eddi g\u1eedi v\u00e0 ng\u01b0\u1eddi nh\u1eadn th\u00f4ng \u0111i\u1ec7p \u1edf hai n\u01a1i kh\u00e1c nhau.\u00a0<\/p>\n

H\u1ecd ph\u1ea3i \u0111\u1ea3m b\u1ea3o r\u1eb1ng, khi h\u1ecd g\u1eb7p m\u1eb7t ho\u1eb7c s\u1eed d\u1ee5ng m\u1ed9t ph\u01b0\u01a1ng ti\u1ec7n th\u00f4ng tin li\u00ean l\u1ea1c chung (h\u1ec7 th\u1ed1ng \u0111i\u1ec7n tho\u1ea1i, d\u1ecbch v\u1ee5 b\u01b0u ch\u00ednh) \u0111\u1ec3 trao m\u00e3 kh\u00f3a cho nhau kh\u00f4ng b\u1ecb ng\u01b0\u1eddi kh\u00e1c nghe tr\u1ed9m hay b\u1ecb l\u1ed9 m\u00e3 kh\u00f3a.<\/p>\n

B\u1edfi v\u00ec n\u1ebfu nh\u01b0 v\u1eady, nh\u1eefng ng\u01b0\u1eddi n\u00e0y sau \u0111\u00f3 c\u00f3 th\u1ec3 s\u1eed d\u1ee5ng m\u00e3 kho\u00e1 \u0111\u1ec3 \u0111\u1ecdc l\u00e9n c\u00e1c th\u00f4ng \u0111i\u1ec7p m\u00e0 c\u00e1c b\u00ean g\u1eedi cho nhau. \u0110i\u1ec1u n\u00e0y l\u00e0m xu\u1ea5t hi\u1ec7n nh\u1eefng tr\u1edf ng\u1ea1i l\u1edbn trong vi\u1ec7c qu\u1ea3n l\u00ed (t\u1ea1o, ph\u00e2n ph\u1ed1i v\u00e0 l\u01b0u gi\u1eef) c\u00e1c m\u00e3 kh\u00f3a.\u00a0<\/p>\n

Do s\u1eed d\u1ee5ng chung m\u1ed9t kho\u00e1, c\u1ea3 ng\u01b0\u1eddi g\u1eedi l\u1eabn ng\u01b0\u1eddi nh\u1eadn th\u00f4ng b\u00e1o \u0111\u1ec1u ph\u1ea3i bi\u1ebft kho\u00e1. Vi\u1ec7c m\u00e3 ho\u00e1 v\u00e0 gi\u1ea3i m\u00e3 th\u00f4ng b\u00e1o s\u1eed d\u1ee5ng m\u00e3 ho\u00e1 \u0111\u1ed1i x\u1ee9ng r\u1ea5t nhanh v\u00e0 hi\u1ec7u qu\u1ea3.\u00a0<\/p>\n

Tuy nhi\u00ean, kho\u00e1 d\u1ec5 b\u1ecb l\u1ed9 v\u00e0 qu\u00e1 tr\u00ecnh ph\u00e2n ph\u1ed1i kho\u00e1 cho c\u00e1c th\u00e0nh vi\u00ean r\u1ea5t kh\u00f3 kh\u0103n do kh\u00f4ng th\u00edch h\u1ee3p trong c\u00e1c m\u00f4i tr\u01b0\u1eddng l\u1edbn, ch\u1eb3ng h\u1ea1n nh\u01b0 Internet. V\u00ec ph\u1ea3i c\u00f3 m\u1ed9t kho\u00e1 ri\u00eang cho m\u1ed7i c\u1eb7p ng\u01b0\u1eddi s\u1eed d\u1ee5ng n\u00ean c\u1ea7n ph\u1ea3i c\u00f3 s\u1ed1 l\u01b0\u1ee3ng l\u1edbn s\u1ef1 k\u1ebft h\u1ee3p c\u00e1c c\u1eb7p kho\u00e1.\u00a0<\/p>\n

\u0110\u1ec3 cho 12 ng\u01b0\u1eddi c\u00f3 th\u1ec3 li\u00ean l\u1ea1c an to\u00e0n v\u1edbi nhau \u0111\u00e3 c\u1ea7n t\u1edbi 66 c\u1eb7p kho\u00e1 ri\u00eang. T\u1ed5ng qu\u00e1t, v\u1edbi N m\u00e1y kh\u00e1ch c\u00e1 nh\u00e2n, c\u1ea7n N(N-1)\/2 c\u1eb7p kho\u00e1.\u00a0<\/p>\n

S\u1eed d\u1ee5ng ph\u01b0\u01a1ng ph\u00e1p m\u00e3 h\u00f3a kh\u00f3a b\u00ed m\u1eadt, m\u1ed9t doanh nghi\u1ec7p r\u1ea5t kh\u00f3 c\u00f3 th\u1ec3 th\u1ef1c hi\u1ec7n vi\u1ec7c ph\u00e2n ph\u1ed1i an to\u00e0n c\u00e1c m\u00e3 kh\u00f3a b\u00ed m\u1eadt v\u1edbi h\u00e0ng ng\u00e0n kh\u00e1ch h\u00e0ng tr\u1ef1c tuy\u1ebfn c\u1ee7a m\u00ecnh tr\u00ean nh\u1eefng m\u1ea1ng th\u00f4ng tin r\u1ed9ng l\u1edbn.\u00a0<\/p>\n

V\u00e0, doanh nghi\u1ec7p s\u1ebd ph\u1ea3i b\u1ecf ra nh\u1eefng chi ph\u00ed kh\u00f4ng nh\u1ecf cho vi\u1ec7c t\u1ea1o m\u1ed9t m\u00e3 kh\u00f3a ri\u00eang v\u00e0 chuy\u1ec3n m\u00e3 h\u00f3a \u0111\u00f3 t\u1edbi m\u1ed9t kh\u00e1ch h\u00e0ng b\u1ea5t k\u1ef3 tr\u00ean Internet khi h\u1ecd c\u00f3 nhu c\u1ea7u giao d\u1ecbch v\u1edbi doanh nghi\u1ec7p.\u00a0<\/p>\n

V\u1edbi nh\u1eefng h\u1ea1n ch\u1ebf tr\u00ean, k\u0129 thu\u1eadt m\u00e3 h\u00f3a kh\u00f3a b\u00ed m\u1eadt kh\u00f3 c\u00f3 th\u1ec3 tr\u1edf th\u00e0nh ph\u01b0\u01a1ng ph\u00e1p m\u00e3 h\u00f3a thu\u1eadn ti\u1ec7n s\u1eed d\u1ee5ng trong c\u00e1c giao d\u1ecbch th\u01b0\u01a1ng m\u1ea1i \u0111i\u1ec7n t\u1eed.<\/p>\n

\u0110\u1ec3 c\u00f3 th\u1ec3 d\u1ec5 d\u00e0ng \u0111\u1ea3m b\u1ea3o an to\u00e0n cho c\u00e1c giao d\u1ecbch tr\u00ean Internet c\u1ea7n c\u00f3 nh\u1eefng k\u0129 thu\u1eadt m\u00e3 h\u00f3a kh\u00e1c thu\u1eadn ti\u1ec7n v\u00e0 hi\u1ec7u qu\u1ea3 h\u01a1n, v\u00e0 k\u0129 thu\u1eadt m\u00e3 h\u00f3a kh\u00f3a c\u00f4ng c\u1ed9ng ra \u0111\u1eddi.<\/p>\n

(T\u00e0i li\u1ec7u tham kh\u1ea3o: B\u00e0i gi\u1ea3ng Th\u01b0\u01a1ng m\u1ea1i \u0110i\u1ec7n t\u1eed, Tr\u1ea7n C\u00f4ng Nghi\u1ec7p, 2008, NXB Tr\u01b0\u1eddng \u0110\u1ea1i h\u1ecdc Kinh t\u1ebf v\u00e0 Qu\u1ea3n tr\u1ecb Kinh doanh)<\/i><\/p>\n<\/p><\/div>\n","protected":false},"excerpt":{"rendered":"

\n M\u00e3 h\u00f3a kh\u00f3a b\u00ed m\u1eadt (ti\u1ebfng Anh: Private key) l\u00e0 m\u1ed9t trong nh\u1eefng k\u0129 thu\u1eadt c\u01a1 b\u1ea3n \u0111\u1ec3 m\u00e3 h\u00f3a th\u00f4ng tin tr\u00ean Internet, v\u00e0 \u0111\u01b0\u1ee3c s\u1eed d\u1ee5ng \u0111\u1ec3 ph\u00f2ng tr\u00e1nh r\u1ee7i ro trong th\u01b0\u01a1ng m\u1ea1i \u0111i\u1ec7n t\u1eed.\n <\/div>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[418],"tags":[],"_links":{"self":[{"href":"https:\/\/masterskills.org\/blog\/wp-json\/wp\/v2\/posts\/33406"}],"collection":[{"href":"https:\/\/masterskills.org\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/masterskills.org\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/masterskills.org\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/masterskills.org\/blog\/wp-json\/wp\/v2\/comments?post=33406"}],"version-history":[{"count":0,"href":"https:\/\/masterskills.org\/blog\/wp-json\/wp\/v2\/posts\/33406\/revisions"}],"wp:attachment":[{"href":"https:\/\/masterskills.org\/blog\/wp-json\/wp\/v2\/media?parent=33406"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/masterskills.org\/blog\/wp-json\/wp\/v2\/categories?post=33406"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/masterskills.org\/blog\/wp-json\/wp\/v2\/tags?post=33406"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}