The transport layer protocols used for real time multimedia, file transfer, DNS and email, respectively are

Using public key cryptography, X adds a digital signature σ to message M, encrypts, and sends it to Y, where it is decrypted. Which one of the following sequences of keys is used for the operations?

Consider an instruction pipeline with five stages without any branch prediction: Fetch Instruction $$(FI),$$ Decode Instruction $$(DI),$$ Fetch Operand $$(FO),$$ Execute Instruction $$(EI)$$ and Write Operand $$(WO).$$ The stage delays for $$FI, DI, FO, EI$$ and $$WO$$ are $$5$$ $$ns,$$ $$7$$ $$ns,$$ $$10$$ $$ns,$$ $$8$$ $$ns$$ and $$6$$ $$ns$$, respectively. There are intermediate storage buffers after each stage and the delay of each buffer is $$1$$ $$ns.$$ A program consisting of $$12$$ instructions $${{\rm I}_1},{{\rm I}_2},{{\rm I}_3},......,\,\,{{\rm I}_{12}}$$ is executed in this pipelined processor. Instruction $${{\rm I}_4}$$ is the only branch instruction and its branch target is $${{\rm I}_9}$$. If the branch is taken during the execution of this program, the time (in $$ns$$) needed to complete the program is

Consider a hypothetical processor with an instruction of type $$LW$$ $$R1, 20(R2),$$ which during execution reads a $$32$$-bit word from memory and stores it in a $$32$$-bit register $$R1.$$ The effective address of the memory location is obtained by the addition of a constant $$20$$ and the contents of register $$R2.$$ Which of the following best reflects the addressing mode implemented by this instruction for the operand in memory?