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kelalaka
kelalaka
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Using a block cipher with using either CTR or GCM mode gives us a stream cipher, the only difference being that CTR does not include ana MAC tag or AAD but GCM does. I think these are the most commonly used modes of operations for block ciphers because ECB is insecure and CBC is not parallelizable.

Does this not reduce the effective algorithm block size to 1 bit as one bit gets mapped to another bit depending on the key streamkeystream bits? Would it not be preferable to keep the block size of a cipher?

Using a block cipher with using either CTR or GCM mode gives us a stream cipher, the only difference being that CTR does not include an MAC tag or AAD but GCM does. I think these are the most commonly used modes of operations for block ciphers because ECB is insecure and CBC is not parallelizable.

Does this not reduce the effective algorithm block size to 1 bit as one bit gets mapped to another bit depending on the key stream bits? Would it not be preferable to keep the block size of a cipher?

Using a block cipher with using either CTR or GCM mode gives us a stream cipher, the only difference being that CTR does not include a MAC tag or AAD but GCM does. I think these are the most commonly used modes of operations for block ciphers because ECB is insecure and CBC is not parallelizable.

Does this not reduce the effective algorithm block size to 1 bit as one bit gets mapped to another bit depending on the keystream bits? Would it not be preferable to keep the block size of a cipher?

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DannyNiu
DannyNiu
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Using a block cipher with using either CTR or GCM mode gives us a stream cipher, the only difference being that CTR does not include an hmacMAC tag or AAD but GCM does. I think these are the most commonly used modes of operations for block ciphers because ECB is insecure and CBC is slownot parallelizable. 

Does this not reduce the effective algorithm block size to 1 bit as one bit gets mapped to another bit depending on the key stream bits? Would it not be preferable to keep the block size of a cipher?

Using a block cipher with using either CTR or GCM mode gives us a stream cipher, the only difference being that CTR does not include an hmac but GCM does. I think these are the most commonly used modes of operations for block ciphers because ECB is insecure and CBC is slow. Does this not reduce the effective algorithm block size to 1 bit as one bit gets mapped to another bit depending on the key stream bits? Would it not be preferable to keep the block size of a cipher?

Using a block cipher with using either CTR or GCM mode gives us a stream cipher, the only difference being that CTR does not include an MAC tag or AAD but GCM does. I think these are the most commonly used modes of operations for block ciphers because ECB is insecure and CBC is not parallelizable. 

Does this not reduce the effective algorithm block size to 1 bit as one bit gets mapped to another bit depending on the key stream bits? Would it not be preferable to keep the block size of a cipher?

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Gamer2015
Gamer2015
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Why are block ciphers mostly used as stream ciphers?

Using a block cipher with using either CTR or GCM mode gives us a stream cipher, the only difference being that CTR does not include an hmac but GCM does. I think these are the most commonly used modes of operations for block ciphers because ECB is insecure and CBC is slow. Does this not reduce the effective algorithm block size to 1 bit as one bit gets mapped to another bit depending on the key stream bits? Would it not be preferable to keep the block size of a cipher?