Security services provided by digital signature
The Digital signature provides following services : 
1. Non forgeable : No one else other than signer can sign it 
2. Sender Authentication : Signer deliberately signed the document as it uses private key 
3. Data integrity : The algorithm uses hashing functionality 
4. Non repudiation : Signer cannot claim he/she didn’t sign it  
5. Tamperproof : Document cannot be altered after signature 
6. Non malleable : Signature cannot be cut /paste to another document 
7. Receiver Authentic : No as it uses only receiver public key 

Hope this helps