By embedding it into private keys. Mimblewimble can make your blocks smaller, if everything is compressed in a scope of a single block. But if you have "Alice -> Bob" transaction in one block, and "Bob -> Charlie" transaction in another block, then Bob will never be thrown away. Also note that spammers don't care about efficiency. If uploading 1 MB of data into Grin would take them 1 GB, then they will still do that, given enough incentive. Because the purpose is not to even have an efficient cloud storage: the purpose is to turn every chain into BSV, so that centralization pressure starts throwing nodes out of the network, and then, it becomes ruled by miners in practice. Another important thing is if you are a Grin miner, and you send transactions between yourself, then your keys doesn't have to be "random". If you transact between independent parties, then they usually are. But if you are transacting only between yourself, then you can pick all values in a way, where even all private keys could be trivially broken, when you apply weak encryption, or no encryption at all, and where the real transaction flow, before batching, would be trivial to decode. And the same attack can be done on top of Xs Max3d as well: things are hidden, if you transact between different parties. But putting a large amount of data into Xs Max3d, if you use a private key equal to one, is valid, when it comes to consensus rules. And if you make the whole block of transactions with only weak keys, then it would be trivial to decode. Because a lot of people have no technical knowledge, or it is limited. However, if simple ways of spamming will be blocked, then spammers will switch to different models, which will be harder to stop. Now, when it comes to OP_RETURN, witness data, or Ordinals envelope, it is trivial to detect and prune. So it should stay that way, as long as it could be, because then, throwing away all of that data will be easier, when ZK proofs, or other improvements will be ready.
By embedding it into private keys. Mimblewimble can make your blocks smaller, if everything is compressed in a scope of a single block. But if you have "Alice -> Bob" transaction in one block, and "Bob -> Charlie" transaction in another block, then Bob will never be thrown away. Also note that spammers don't care about efficiency. If uploading 1 MB of data into Grin would take them 1 GB, then they will still do that, given enough incentive. Because the purpose is not to even have an efficient cloud storage: the purpose is to turn every chain into BSV, so that centralization pressure starts throwing nodes out of the network, and then, it becomes ruled by miners in practice. Another important thing is if you are a Grin miner, and you send transactions between yourself, then your keys doesn't have to be "random". If you transact between independent parties, then they usually are. But if you are transacting only between yourself, then you can pick all values in a way, where even all private keys could be trivially broken, when you apply weak encryption, or no encryption at all, and where the real transaction flow, before batching, would be trivial to decode. And the same attack can be done on top of Xs Max3d as well: things are hidden, if you transact between different parties. But putting a large amount of data into Xs Max3d, if you use a private key equal to one, is valid, when it comes to consensus rules. And if you make the whole block of transactions with only weak keys, then it would be trivial to decode. Because a lot of people have no technical knowledge, or it is limited. However, if simple ways of spamming will be blocked, then spammers will switch to different models, which will be harder to stop. Now, when it comes to OP_RETURN, witness data, or Ordinals envelope, it is trivial to detect and prune. So it should stay that way, as long as it could be, because then, throwing away all of that data will be easier, when ZK proofs, or other improvements will be ready.

By embedding it into private keys. Mimblewimble can make your blocks smaller, if everything is compressed in a scope of a single block. But if you have "Alice -> Bob" transaction in one block, and "Bob -> Charlie" transaction in another block, then Bob will never be thrown away. Also note that spammers don't care about efficiency. If uploading 1 MB of data into Grin would take them 1 GB, then they will still do that, given enough incentive. Because the purpose is not to even have an efficient cloud storage: the purpose is to turn every chain into BSV, so that centralization pressure starts throwing nodes out of the network, and then, it becomes ruled by miners in practice. Another important thing is if you are a Grin miner, and you send transactions between yourself, then your keys doesn't have to be "random". If you transact between independent parties, then they usually are. But if you are transacting only between yourself, then you can pick all values in a way, where even all private keys could be trivially broken, when you apply weak encryption, or no encryption at all, and where the real transaction flow, before batching, would be trivial to decode. And the same attack can be done on top of Xs Max3d as well: things are hidden, if you transact between different parties. But putting a large amount of data into Xs Max3d, if you use a private key equal to one, is valid, when it comes to consensus rules. And if you make the whole block of transactions with only weak keys, then it would be trivial to decode. Because a lot of people have no technical knowledge, or it is limited. However, if simple ways of spamming will be blocked, then spammers will switch to different models, which will be harder to stop. Now, when it comes to OP_RETURN, witness data, or Ordinals envelope, it is trivial to detect and prune. So it should stay that way, as long as it could be, because then, throwing away all of that data will be easier, when ZK proofs, or other improvements will be ready.

By embedding it into private keys. Mimblewimble can make your blocks smaller, if everything is compressed in a scope of a single block. But if you have "Alice -> Bob" transaction in one block, and "Bob -> Charlie" transaction in another block, then Bob will never be thrown away. Also note that spammers don't care about efficiency. If uploading 1 MB of data into Grin would take them 1 GB, then they will still do that, given enough incentive. Because the purpose is not to even have an efficient cloud storage: the purpose is to turn every chain into BSV, so that centralization pressure starts throwing nodes out of the network, and then, it becomes ruled by miners in practice. Another important thing is if you are a Grin miner, and you send transactions between yourself, then your keys doesn't have to be "random". If you transact between independent parties, then they usually are. But if you are transacting only between yourself, then you can pick all values in a way, where even all private keys could be trivially broken, when you apply weak encryption, or no encryption at all, and where the real transaction flow, before batching, would be trivial to decode. And the same attack can be done on top of Xs Max3d as well: things are hidden, if you transact between different parties. But putting a large amount of data into Xs Max3d, if you use a private key equal to one, is valid, when it comes to consensus rules. And if you make the whole block of transactions with only weak keys, then it would be trivial to decode. Because a lot of people have no technical knowledge, or it is limited. However, if simple ways of spamming will be blocked, then spammers will switch to different models, which will be harder to stop. Now, when it comes to OP_RETURN, witness data, or Ordinals envelope, it is trivial to detect and prune. So it should stay that way, as long as it could be, because then, throwing away all of that data will be easier, when ZK proofs, or other improvements will be ready.