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Multiple encryption doesn't increase bit strength anymore than using a longer key. You seem to think an attacker could only try one key but they wouldn't. They would try multiple keys to see if the output of multiple rounds produces the plaintext. You might be thinking well that would be "hard" but it isn't any harder than an equivalent single key.

For example symmetric encryption with a 256 bit key will take on average 2^2562256 attempts to find the proper key by brute force. Doing two rounds with 128 bit keys will take (2^128)*(2^128)2128 × 2128 = 2^2562256 attempts as well. Now you might say well I would use two rounds with 256 bit keys. Ok that requires 512 bits worth of keys. It isn't any stronger than a single round with a 512 bit key.

The reality is anything beyond 128 is beyond brute force. There isn't sufficient energy in our star to count to 2^2562256 before it burns out much less brute force a key. Strong cryptography is strong. You don't need to invent clever ways to obfuscate it.

You could say Hello NSA here is the encrypted file. It uses AES-256 in CBC block mode and here is the IV. Try and break it. Strong encryption is strong. Obligatory reference to xkcd wrench scenario aside they aren't breaking it. They could bankrupt the country and build a planetary sized computer and they aren't breaking it. 2^256 2256 is a lot bigger than you think. So if 2^1282128 or 2^2562256 is so large as to be beyond brute force why would you need multiple of that? It protects against a non-existent threat.

The weak link is how did you generate that key. Was is derived from a password. Maybe one as weak as "P@ssw0rd!"? Well that is a lot easier to attack than a random 256 bit key? The "weakness" in modern cryptography isn't the primitives. They are well understood. It is all the implementation details. If the block mode CTR and you reused the IV? Your weak. Is it derived from a weak password? Your weak. Did you do a simple unsalted hash of a password instead of a using a KDF? Your weak. Does your PRNG have a flaw or backdoor? Your weak. Nobody brute forces keys with 128 bits of entropy. Nobody. So your solution is one in search of a problem. If your implementation is flawed it very likely is flawed for multiple keys as well so you are still weak. Simple is good, there is less to get wrong.

Multiple encryption doesn't increase bit strength anymore than using a longer key. You seem to think an attacker could only try one key but they wouldn't. They would try multiple keys to see if the output of multiple rounds produces the plaintext. You might be thinking well that would be "hard" but it isn't any harder than an equivalent single key.

For example symmetric encryption with a 256 bit key will take on average 2^256 attempts to find the proper key by brute force. Doing two rounds with 128 bit keys will take (2^128)*(2^128) = 2^256 attempts as well. Now you might say well I would use two rounds with 256 bit keys. Ok that requires 512 bits worth of keys. It isn't any stronger than a single round with a 512 bit key.

The reality is anything beyond 128 is beyond brute force. There isn't sufficient energy in our star to count to 2^256 before it burns out much less brute force a key. Strong cryptography is strong. You don't need to invent clever ways to obfuscate it.

You could say Hello NSA here is the encrypted file. It uses AES-256 in CBC block mode and here is the IV. Try and break it. Strong encryption is strong. Obligatory reference to xkcd wrench scenario aside they aren't breaking it. They could bankrupt the country and build a planetary sized computer and they aren't breaking it. 2^256 is a lot bigger than you think. So if 2^128 or 2^256 is so large as to be beyond brute force why would you need multiple of that? It protects against a non-existent threat.

The weak link is how did you generate that key. Was is derived from a password. Maybe one as weak as "P@ssw0rd!"? Well that is a lot easier to attack than a random 256 bit key? The "weakness" in modern cryptography isn't the primitives. They are well understood. It is all the implementation details. If the block mode CTR and you reused the IV? Your weak. Is it derived from a weak password? Your weak. Did you do a simple unsalted hash of a password instead of a using a KDF? Your weak. Does your PRNG have a flaw or backdoor? Your weak. Nobody brute forces keys with 128 bits of entropy. Nobody. So your solution is one in search of a problem. If your implementation is flawed it very likely is flawed for multiple keys as well so you are still weak. Simple is good, there is less to get wrong.

Multiple encryption doesn't increase bit strength anymore than using a longer key. You seem to think an attacker could only try one key but they wouldn't. They would try multiple keys to see if the output of multiple rounds produces the plaintext. You might be thinking well that would be "hard" but it isn't any harder than an equivalent single key.

For example symmetric encryption with a 256 bit key will take on average 2256 attempts to find the proper key by brute force. Doing two rounds with 128 bit keys will take 2128 × 2128 = 2256 attempts as well. Now you might say well I would use two rounds with 256 bit keys. Ok that requires 512 bits worth of keys. It isn't any stronger than a single round with a 512 bit key.

The reality is anything beyond 128 is beyond brute force. There isn't sufficient energy in our star to count to 2256 before it burns out much less brute force a key. Strong cryptography is strong. You don't need to invent clever ways to obfuscate it.

You could say Hello NSA here is the encrypted file. It uses AES-256 in CBC block mode and here is the IV. Try and break it. Strong encryption is strong. Obligatory reference to xkcd wrench scenario aside they aren't breaking it. They could bankrupt the country and build a planetary sized computer and they aren't breaking it. 2256 is a lot bigger than you think. So if 2128 or 2256 is so large as to be beyond brute force why would you need multiple of that? It protects against a non-existent threat.

The weak link is how did you generate that key. Was is derived from a password. Maybe one as weak as "P@ssw0rd!"? Well that is a lot easier to attack than a random 256 bit key? The "weakness" in modern cryptography isn't the primitives. They are well understood. It is all the implementation details. If the block mode CTR and you reused the IV? Your weak. Is it derived from a weak password? Your weak. Did you do a simple unsalted hash of a password instead of a using a KDF? Your weak. Does your PRNG have a flaw or backdoor? Your weak. Nobody brute forces keys with 128 bits of entropy. Nobody. So your solution is one in search of a problem. If your implementation is flawed it very likely is flawed for multiple keys as well so you are still weak. Simple is good, there is less to get wrong.

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Multiple encryption doesn't increase bit strength anymore than using a longer key. You seem to think an attacker could only try one key but they wouldn't. They would try multiple keys to see if the output of multiple rounds produces the plaintext. You might be thinking well that would be "hard" but it isn't any harder than an equivalent single key.

For example symmetric encryption with a 256 bit key will take on average 2^256 attempts to find the proper key by brute force. Doing two rounds with 128 bit keys will take (2^128)^128*(2^128) = 2^256 attempts as well. Now you might say well I would use two rounds with 256 bit keys. Ok that requires 512 bits worth of keys. It isn't any stronger than a single round with a 512 bit key.

The reality is anything beyond 128 is beyond brute force. There isn't sufficient energy in our star to count to 2^256 before it burns out much less brute force a key. Strong cryptography is strong. You don't need to invent clever ways to obfuscate it.

You could say Hello NSA here is the encrypted file. It uses AES-256 in CBC block mode and here is the IV. Try and break it. Strong encryption is strong. Obligatory reference to xkcd wrench scenario aside they aren't breaking it. They could bankrupt the country and build a planetary sized computer and they aren't breaking it. 2^256 is a lot bigger than you think. So if 2^128 or 2^256 is so large as to be beyond brute force why would you need multiple of that? It protects against a non-existent threat.

The weak link is how did you generate that key. Was is derived from a password. Maybe one as weak as "P@ssw0rd!"? Well that is a lot easier to attack than a random 256 bit key? The "weakness" in modern cryptography isn't the primitives. They are well understood. It is all the implementation details. If the block mode CTR and you reused the IV? Your weak. Is it derived from a weak password? Your weak. Did you do a simple unsalted hash of a password instead of a using a KDF? Your weak. Does your PRNG have a flaw or backdoor? Your weak. Nobody brute forces keys with 128 bits of entropy. Nobody. So your solution is one in search of a problem. If your implementation is flawed it very likely is flawed for multiple keys as well so you are still weak. Simple is good, there is less to get wrong.

Multiple encryption doesn't increase bit strength anymore than using a longer key. You seem to think an attacker could only try one key but they wouldn't. They would try multiple keys to see if the output of multiple rounds produces the plaintext. You might be thinking well that would be "hard" but it isn't any harder than an equivalent single key.

For example symmetric encryption with a 256 bit key will take on average 2^256 attempts to find the proper key by brute force. Doing two rounds with 128 bit keys will take (2^128)^128 = 2^256 attempts as well. Now you might say well I would use two rounds with 256 bit keys. Ok that requires 512 bits worth of keys. It isn't any stronger than a single round with a 512 bit key.

The reality is anything beyond 128 is beyond brute force. There isn't sufficient energy in our star to count to 2^256 before it burns out much less brute force a key. Strong cryptography is strong. You don't need to invent clever ways to obfuscate it.

You could say Hello NSA here is the encrypted file. It uses AES-256 in CBC block mode and here is the IV. Try and break it. Strong encryption is strong. Obligatory reference to xkcd wrench scenario aside they aren't breaking it. They could bankrupt the country and build a planetary sized computer and they aren't breaking it. 2^256 is a lot bigger than you think. So if 2^128 or 2^256 is so large as to be beyond brute force why would you need multiple of that? It protects against a non-existent threat.

The weak link is how did you generate that key. Was is derived from a password. Maybe one as weak as "P@ssw0rd!"? Well that is a lot easier to attack than a random 256 bit key? The "weakness" in modern cryptography isn't the primitives. They are well understood. It is all the implementation details. If the block mode CTR and you reused the IV? Your weak. Is it derived from a weak password? Your weak. Did you do a simple unsalted hash of a password instead of a using a KDF? Your weak. Does your PRNG have a flaw or backdoor? Your weak. Nobody brute forces keys with 128 bits of entropy. Nobody. So your solution is one in search of a problem. If your implementation is flawed it very likely is flawed for multiple keys as well so you are still weak. Simple is good, there is less to get wrong.

Multiple encryption doesn't increase bit strength anymore than using a longer key. You seem to think an attacker could only try one key but they wouldn't. They would try multiple keys to see if the output of multiple rounds produces the plaintext. You might be thinking well that would be "hard" but it isn't any harder than an equivalent single key.

For example symmetric encryption with a 256 bit key will take on average 2^256 attempts to find the proper key by brute force. Doing two rounds with 128 bit keys will take (2^128)*(2^128) = 2^256 attempts as well. Now you might say well I would use two rounds with 256 bit keys. Ok that requires 512 bits worth of keys. It isn't any stronger than a single round with a 512 bit key.

The reality is anything beyond 128 is beyond brute force. There isn't sufficient energy in our star to count to 2^256 before it burns out much less brute force a key. Strong cryptography is strong. You don't need to invent clever ways to obfuscate it.

You could say Hello NSA here is the encrypted file. It uses AES-256 in CBC block mode and here is the IV. Try and break it. Strong encryption is strong. Obligatory reference to xkcd wrench scenario aside they aren't breaking it. They could bankrupt the country and build a planetary sized computer and they aren't breaking it. 2^256 is a lot bigger than you think. So if 2^128 or 2^256 is so large as to be beyond brute force why would you need multiple of that? It protects against a non-existent threat.

The weak link is how did you generate that key. Was is derived from a password. Maybe one as weak as "P@ssw0rd!"? Well that is a lot easier to attack than a random 256 bit key? The "weakness" in modern cryptography isn't the primitives. They are well understood. It is all the implementation details. If the block mode CTR and you reused the IV? Your weak. Is it derived from a weak password? Your weak. Did you do a simple unsalted hash of a password instead of a using a KDF? Your weak. Does your PRNG have a flaw or backdoor? Your weak. Nobody brute forces keys with 128 bits of entropy. Nobody. So your solution is one in search of a problem. If your implementation is flawed it very likely is flawed for multiple keys as well so you are still weak. Simple is good, there is less to get wrong.

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Multiple encryption doesn't increase bit strength anymore than using a longer key. You seem to think an attacker could only try one key but they wouldn't. They would try multiple keys to see if the output of multiple rounds produces the plaintext. You might be thinking well that would be "hard" but it isn't any harder than an equivalent single key.

For example symmetric encryption with a 256 bit key will take on average 2^256 attempts to find the proper key by brute force. Doing two rounds with 128 bit keys will take (2^128)^128 = 2^256 attempts as well. Now you might say well I would use two rounds with 256 bit keys. Ok that requires 512 bits worth of keys. It isn't any stronger than a single round with a 512 bit key.

The reality is anything beyond 128 is beyond brute force. There isn't sufficient energy in our star to count to 2^256 before it burns out much less brute force a key. Strong cryptography is strong. You don't need to invent clever ways to obfuscate it.

You could say Hello NSA here is the encrypted file. It uses AES-256 in CBC block mode and here is the IV. Try and break it. Strong encryption is strong. Obligatory reference to xkcd wrench scenario aside they aren't breaking it. They could bankrupt the country and build a planetary sized computer and they aren't breaking it. 2^256 is a lot bigger than you think. So if 2^128 or 2^256 is so large as to be beyond brute force why would you need multiple of that? It protects against a non-existent threat.

The weak link is how did you generate that key. Was is derived from a password. Maybe one as weak as "P@ssw0rd!"? Well that is a lot easier to attack than a random 256 bit key? The "weakness" in modern cryptography isn't the primitives. They are well understood. It is all the implementation details. If the block mode CTR and you reused the IV? Your weak. Is it derived from a weak password? Your weak. Did you do a simple unsalted hash of a password instead of a using a KDF? Your weak. Does your PRNG have a flaw or backdoor? Your weak. Nobody brute forces keys with 128 bits of entropy. Nobody. So your solution is one in search of a problem. If your implementation is flawed it very likely is flawed for multiple keys as well so you are still weak. Simple is good, there is less to get wrong.