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Assuming all messages and their signatures are available to the attacker, is it secure to use the same RSA private key to sign many messages (roughly $10^{6}$) via PKCS#11 CKM_SHA256_RSA_PKCS using a reasonably long (i.e. 2048 bit) key?

For reference, CKM_SHA256_RSA_PKCS is described as follows:

The PKCS #1 v1.5 RSA signature with SHA-256 mechanism, denoted CKM_SHA256_RSA_PKCS, performs single- and multiple-part digital signatures and verification operations without message recovery. The operations performed are as described initially in PKCS #1 v1.5 with the object identifier sha256WithRSAEncryption, and as in the scheme RSASSA-PKCS1-v1_5 in the current version of PKCS #1, where the underlying hash function is SHA-256.

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