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See comment from user Xander how recommend this: Using the same secret key for encryption and authentication in a Encrypt-then-MAC scheme Thomas Pornin: Brute forcing the key would hardly be an issue: 128-bit keys (assuming they have been properly generated) are in a space which is way too large to be successfully explored by brute force; and 256-...


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If your main objective is to ensure integrity and authenticity, and not confidentiality, it sounds like what you want is not encryption, but message authentication (symmetric, like HMAC) or a digital signature (asymmetric, like RSA). Since you mention third parties, it's likely that signing with an asymmetric system should be used, since with a symmetric ...


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Is is difficult to to implement either? No not really, as long as you use a vetted and verified implemented library. AES is much faster than RSA, but as you only sign a hash the amount of data operated on should not be much of a concern. RSA (is that is the assym. alogrithm you wish to use) is 2048 (see) and 256 for AES. With AES you would probably want to ...


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AES is considered today to be the best symetric crypto algorithm to use. AES-256 is perfect, and with 40 characters, this is more than enough.


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You shouldn't be using openssl to encrypt files. You should use gpg -c instead (which encrypts it with a symmetric cipher). Using openssl causes it to lack authentication, key strenthening, etc. To answer the question though, a 40 character password (assuming it's entirely random chosen from a 95 character keyboard, since you gave no information about the ...


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Regarding how long it would take, if we use a tool like crunch to generate the wordlist to use for cracking said PDF file, the output would be this: [root@yokai ~]# crunch 20 20 ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789 Crunch will now generate the following amount of data: 11388113619364347904 bytes 10860551471104 MB 10606007296 GB 10357429 TB 10114 PB Crunch ...


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The only attack that doesn't take millions of years requires a lot of money. Custom build a 32 nm AES cracker Build 50 chip plants to make these chips Spend a year making chips Build a giant cluster of systems Run the cluster for 1 year Note that the R&D cost on the chip will be anywhere from $50-$250 million, the plants will be $1-2 Billion each and ...


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No, this is not possible. If you change a single bit in a block that is put through the cipher then all bits change with a certainty of 50% due to the avalanche effect. So even though only one bit will be changed in the next block, the current block will still completely change. Differently said, AES is a block cipher and a keyed block cipher is a pseudo ...


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The encryption key for full disk or partial disk encryption are stored in RAM while the OS is operational. How are the disk encryption keys protected when a laptop is locked? If the device is shut down, then RAM is cleared, thereby securing your keys. If RAM is really cold, it will last awhile longer, so one technique to extracting RAM is to freeze ...


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Short answer is "data STILL readable but just behind a password". It is rare that anything in RAM is encrypted, simply because it would require some sort of a password to decrypt, and most passwords would reside in RAM anyhow. Going a bit further with this, the decryption password for the majority of disk-encryption programs would actually also (ironically)...


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Always encrypting the same text to the same value leads to data leakage, violating semantic security. To prevent this, CBC mode uses an initialization vector (IV). The IV is just a random string of bits equal to the block size of the cipher. This is XORed with the first block of clear-text to be encrypted. This makes the first encrypted block random. Each ...


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OpenSSL implements almost a dozen symmetric ciphers, and several dozen cipher-mode combinations, but provides a (nearly) single interface to all of them in the EVP module (i.e. external function and type names beginning EVP_) documented here online or in the (crosslinked) man page for EVP_{Cipher,Encrypt,Decrypt}* and EVP_CIPHER_* and EVP_CIPHER_CTX_* on any ...


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By the way this 128bit AES comes from the modems within the telematics system, which is based on telecoms ITU-T security which incidentally covers many other aspects such as privacy, data confidentiality,authentication, integrity, non-repudiation, access control, communication security, and availability as shown in the Figure below: So AES-128 CMAC refers ...


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This is impossible as @mr-e said: CBC works by XORing the plaintext with the IV / previous ciphertext before encryption. Without access to the ciphertext you cannot alter the rounds.


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an encryption patent is a contradiction in terms these days. nobody (in the large) is going to spend the effort to evaluate a patented method. at best, you would read the patent filing and determine that it's a cheesy version of something that exists and expose yourself to triple damages because you read a patent that should have been rejected based on an ...



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