密码学的基础知识英文翻译

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偷听或截获到密钥的

任何人，就能够阅读，修改和伪造用这个密钥 加密或认证

的所有信息。无论

DES

还是

midnight

上尉的秘密译码器圆环，

传统加密方法

的永恒问题就是密钥的发布

,

怎样才能 使接

收者得到密钥而不被其他人截获

呢？

根据美国的数字签名的数字式

multisignature

标准

DSA

提出二份计划。

他们中的一个是一新的连续数字式

multisignature

，

并且其他是一新

的广播

数字式

multisignature

。

这些计划安全根据解决分离对数问题。

署名的参量

在计

划任意地被选择，

并且计划是高安全。

而且，

计划的最初的阶段是简

单的

;

他们比广播

数字式

multisignature

计划可以防止有些参加者欺诈其他

和有更低的通信费用，

并且计

划是实用的。

The Basics of Cryptography

In

public

key

cryptographic

system,

in

order

to

safeguard

the

encryption

operation the convenience, has had the key technology. At present, the public key

cryptographic

system

all

uses

two

different

keys,

key

is

private,

another

is

public.

According to the different applicationrequest, the transmission only then uses its

private key or the receiving end public key or simultaneously uses the two to carry

out

the

password

encryption

function.

The

asymmetrical

encryption

algorithm

carries

on

when

the

digital

signature

uses

two

keys:The

public

key

(publick

ey)

and

the

private

key

(private

key),

uses

in

separately

to

the

data

encryption

and

the

decipher,

namely

if uses the public key to carry on the encryption for the data,only then can carry

on

the

decipher

with

the

corresponding

private

key;If

carries

on

the

encryption

with

the

private

key

to

the

data,

then

only

then

can

decipher

with

the

corresponding

public

key. Any has the transmitting end public key people all to be possible to originate

true through the key confirmation definite orders. As a result of the transmitting

end

private

key

secrecy,

causes

the

receiving

end

to

be

possible

to

refuse

to

accept

this text according to the confirmation result, also can cause other people to be

unable the forge text.

Keys

A

key

is

a

value

that

works

with

a

cryptographic

algorithm

to

produce

a

specific

ciphertext. Keys are basically really, really, really big numbers. Key size is

measured

in

bits;

the

number

representing

a

1024-bit

key

is

darn

huge.

In

public

key

cryptography, the bigger the key, the more secure the ciphertext. However, public

key size and conventional cryptography's secret key size are totally unrelated. A

conventional 80-bit key has the equivalent strength of a 1024-bit public key. A

conventional 128-bit key is equivalent to a 3000-bit public key. Again, the bigger

the key, the more secure, but the algorithms used for each type of cryptography are

very

different

and

thus

comparison

is

like

that

of

apples

to

oranges.

While

the

public

and

private

keys

are

mathematically

related,

it's

very

difficult

to

derive

the

private

key given only the public key; however, deriving the

private

key is

always possible

given enough time and computing power. This makes it very important to pick keys of

the right size; large enough to be secure, but small enough to be applied fairly

quickly.

Additionally,

you need

to consider who might be trying to

read your files,

how

determined

they

are,

how

much

time

they

have,

and

what

their

resources

might

be.

Larger keys will be cryptographically secure for a longer period of time. If what

you want to encrypt needs to be hidden for many years, you might want to use a very

large key. Of course, who knows how long it will take to determine your key using

tomorrow's

faster,

more

efficient

computers?

There

was

a

time

when

a

56-bit

symmetric

key

was

considered

extremely

safe.

Keys

are

stored

in

encrypted

form.

PGP

stores

the

keys in two files on your hard disk; one for public keys and one for private keys.

These files are called keyrings. As you use PGP, you will typically add the public

keys

of

your

recipients

to

your

public

keyring.

Your

private

keys

are

stored

on

your

private

keyring.

If

you

lose

your

private

keyring,

you

will

be

unable

to

decrypt

any

information encrypted to keys on that ring.

Key organizational structure

The

existing

key

management

system

management

system

has

all

used

the

hierarchical key structure. The hierarchical key structure and the overall system

key

control

relations

are

the

correspondence,

according

to

the

key

function

and

the

type and between them the mutual control relations, may the different type the key

divides into the level key, two levels of keys,

?

n level key, thus constitutes a

hierarchical

key

system.

Among

them,

system

use

level

key

K:Through

algorithm

f,Protects two levels of keys (level key use physics method or alternative means

carries on protection), uses two levels of keys to pass algorithm f:Protects three

levels

of

keys,

by

this

analogy,

until

finally

uses

the

n

level

key

to

pass

algorithm

f. Protection definite orders with encryption process march, each key

content dynamic change, but this kind of change rule controls the lowest level by