PlainText BASE64 encoded after transposition, the probability that the encoding after transposition can be cracked

Base64 in the Code table of the

First use Base64 regular code, after encoding the plaintext, the encoded plaintext position is disturbed
For example, the normal Base64 code after a change b,b replaced with a c,c for a, in this way to random exchange

1. This time I know the transposition of the coded transposition order.
2. Is not aware of this transposition of the code is replaced by what string

This time other people do not know how much probability to break after transposition of the code.

Reply to discussion (solution)

Base64 is made up of 64 symbols, so the probability of cracking is 1/64! (one of the factorial points of 64)

The method of decoding is to traverse 64 symbols to complete the result set, try each

It's going to be base64. After the civilized normal code encryption,

Assuming that 2-bit lengths are randomly replaced in 64 encodings, the probability of deciphering is one of 4096 points.

Example: Base64 encoding after encoding the value of random disruption, after the length of the encoding is still 12 bits after the probability of breaking 64 square 12

Assuming that the computer computes 1 million times a second, it takes about 1,518,250,54.,104,605 years to decode.

Note: Base64 after transposition if you want to change back, in the middle of the calculation will produce non-garbled plaintext, but this clear text is not your actual civilization value

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