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8

DES has a block size of 8 bytes. Two blocks therefore come to 16 bytes. It looks like Adbobe were encrypting passwords using two blocks of 3-DES in ECB mode. Because all these passwords are eight bytes long, the second block is empty and is just filled with zeros. The second block gets started at all because of the string-terminating NUL character at the ...

6

The article mentions that 3-DES was used to encrypt these passwords in ECB mode. DES has a 64-bit/8-byte block. So let's say you use ECB to encrypt a nine byte password. The first 8-bytes are encrypted using ECB. So far so good. But what happens when we come to the ninth byte? Well we're now in a new block but only the first byte is populated with any ...

5

Note: I'll disregard the base64 encoding in the following text; the base64 encoding does not change the properties of the generated ciphertext. What you are running into is padding together with ECB mode. This padding can be any static padding. Most common is PKCS#5 padding, but zero padding is also possible. It is not possible to test which padding is ...

3

Assuming: the objective is to protect the confidentiality of the user names from an attacker having read access to the encrypted data, the ability to add usernames of her choice, and nothing else (in particular, no access to the key, even by proxy of a computer or device holding the key, or side channel); the IV is randomly chosen for each individual ...

3

If there was a full 64-bit block of known plaintext, there would be a very fast attack using precomputation. You can build a precomputed table of all $2^{40}$ ciphertexts. Once you've got the precomputed table, recovering a key (given a ciphertext) would require just a single lookup in the table, so recovering a key would be extremely fast. Storing that ...

2

There is a NIST definition of CTS (CipherText Stealing) mode at: http://csrc.nist.gov/publications/nistpubs/800-38a/addendum-to-nist_sp800-38A.pdf. The title of that addendum answers the question: "Recommendation for Block Cipher Modes of Operation: Three Variants of Ciphertext Stealing for CBC Mode". The paper is also useful to understand that there are ...

2

I think what you are looking for is a Password-Based Key Derivation Function (PBKDF). You can take a moderately strong password, like 12-14 random letters and numbers (no dictionary words though!), and throw it into the PBKDF function together with some other parameters, e.g. salt, number of iterations and the desired key length. After that you have a ...

1

Search for passwords on IT Security and you will find tons of advice on how to store passwords, and how not to. Your scheme is not a good method for hashing passwords: it is a fast hash, it lacks any salt, and it unnecessarily limits the password length. People have studied this at great length: before trying to re-invent the wheel, I suggest you read up ...

1

What you are looking for is a Pseudo Random Function that should be indistinguishable from uniform, even if the key material that is passed to it is not. One potential problem with your scheme is that the AES key schedule is not particularly good at extracting the entropy from keys that are not selected (pseudo-)randomly, such as passwords and pass-phrases. ...

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