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Using CryptoJS 3.1 I noticed that using 3Des, the encrypted message always start with

U2FsdGVkX1

Why is the first part of the encryption always the same?

What information does this hold and how does that information become U2FsdGVkX1?

Mike Edward Moras
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Thomas
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1 Answers1

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The answer is:

Why do the encrypted files always start with "Salted__" ("U2FsdGVkX1" in base64)? Isn't giving away information like this insecure?

The encrypted files must always start with "Salted__" to interoperate with OpenSSL. OpenSSL expects this. The 8 bytes that spell "Salted__" are always immediately followed by another random 8 bytes of salt. The encrypted stream starts at the 17th byte. This way, even if you use the same password to encrypt 2 different files, the actual secret keys used to encrypt these 2 files are very different.

It is possible to omit the salt, but this is highly discouraged

source: http://juliusdavies.ca/commons-ssl/pbe.html

Muhammad Dyas Yaskur
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woliveirajr
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